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business growth

Business Management

Study Manuals

Diploma in

Business Management

SYSTEMS ANALYSIS

AND DESIGN

The Association of Business Executives


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Diploma in Business Management

SYSTEMS ANALYSIS AND DESIGN

Contents

Unit Title Page

Introduction to the Study Manual v

Syllabus vii

1 Information and Systems 1

Information and Data 3Information Needs 3Types of Information 5Management Information 8Systems Theory 10Objectives of a System 12Information Systems 13Types of Information System 14

2 The Systems Development Life Cycle 17Introduction 18The SDLC 18The Waterfall Model 21

Advantages of the SDLC 22Disadvantages of the SDLC 23Conclusion 23

3 System Specification 25Introduction 27The Development Life Cycle 27Statement of Requirements 30The Personnel Involved 33Systems Investigation 39

The Feasibility or Initial Study 47Requirements Specification 51Using Consultants 52

4 System Design 53Logical and Physical Design 54The Design Stage 56System Design Specification 58Design Considerations 59Human-Computer Interface 62


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Unit Title Page

5 Approaches to Systems Analysis and Design 67Introduction 69Hard and Soft Systems 69The Soft Systems Methodology (SSM) 70Structured Systems Analysis and Design Method (SSADM) 75Object-Oriented Analysis and Design (OOAD) 79Web Informations Systems Development 81Rapid Application Development (RAD) 82Joint Application Development (JAD) 83Skilled Small Team Development 83Prototyping 84CASE Tools 85

6 Data Flow Diagrams 87

Introduction 88An Example System 88Data Flow Diagrams (DFDs) 89Levels of Data Flow Diagram 93Drawing Data Flow Diagrams 95Physical and Logical DFDs 96

Advantages and Disadvantages of DFDs 98

7 Data Modelling 103Introduction 104Entities, Attributes and Relationships 104Entity Relationships 105

Optional and Mandatory Relationships 108Many-to-Many Relationships 110What Happens Next? 111Data Dictionaries 113

8 Entity Life Histories (ELH) 119Introduction 120ELH Notation 120Interrelationship between the DFD, Entity-Relationship Model and theELH 125Examples 126

9 Object Orientation and the Unified Modelling Language (UML) 131Introduction 132Background 132Objects and Object Classes 133Class Diagrams 134Use Cases 144Sequence Diagrams 146Conclusion 148


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Unit Title Page

10 Standards and Documentation 149Introduction 150Role and Scope of Standards 150The Standards Manual 153Other Documentation 153Using Standard Forms 156

11 System Implementation 157The Implementation Process 158User Involvement 161Changeover Strategies 161Post-Implementation Reviews 167Training 171

12 Management of Change and Project Management 175Management of Change 176Project Management 179Problems During Development 180Rules of Project Management 182Specific Development Controls 183Control Techniques 184

13 System Maintenance and Security 191Monitoring 192Systems Maintenance 193Database Maintenance 194

System Enhancements 195Need for System Security 196Security Measures 199


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v

Introduction to the Study Manual

Welcome to this study manual for Systems Analysis and Design.

The manual has been specially written to assist you in your studies for the ABE Diploma inBusiness Management and is designed to meet the learning outcomes specified for this

module in the syllabus. As such, it provides a thorough introduction to each subject area andguides you through the various topics which you will need to understand. However, it is notintended to "stand alone" as the only source of information in studying the module, and weset out below some guidance on additional resources which you should use to help inpreparing for the examination.

The syllabus for the module is set out on the following pages and you should read thiscarefully so that you understand the scope of the module and what you will be required toknow for the examination. Also included in the syllabus are details of the method ofassessment the examination and the books recommended as additional reading.

The main study material then follows in the form of a number of study units as shown in thecontents. Each of these units is concerned with one topic area and takes you through all thekey elements of that area, step by step. You should work carefully through each study unit inturn, tackling any questions or activities as they occur, and ensuring that you fully understandeverything that has been covered before moving on to the next unit. You will also find it veryhelpful to use the additional reading to develop your understanding of each topic area whenyou have completed the study unit.

Additional resources

ABE website www.abeuk.com. You should ensure that you refer to the MembersArea of the website from time to time for advice and guidance on studying andpreparing for the examination. We shall be publishing articles which provide generalguidance to all students and, where appropriate, also give specific information about

particular modules, including updates to the recommended reading and to the studyunits themselves.

Additional reading It is important you do not rely solely on this manual to gain theinformation needed for the examination on this module. You should, therefore, studysome other books to help develop your understanding of the topics underconsideration. The main books recommended to support this manual are included inthe syllabus which follows, but you should also refer to the ABE website for furtherdetails of additional reading which may be published from time to time.

Newspapers You should get into the habit of reading a good quality newspaper on aregular basis to ensure that you keep up to date with any developments which may berelevant to the subjects in this module.

Your college tutor If you are studying through a college, you should use your tutors tohelp with any areas of the syllabus with which you are having difficulty. That is whatthey are there for! Do not be afraid to approach your tutor for this module to seekclarification on any issue, as they will want you to succeed as much as you want to.

Your own personal experience The ABE examinations are not just about learning lotsof facts, concepts and ideas from the study manual and other books. They are alsoabout how these are applied in the real world and you should always think how thetopics under consideration relate to your own work and to the situation at your ownworkplace and others with which you are familiar. Using your own experience in thisway should help to develop your understanding by appreciating the practicalapplication and significance of what you read, and make your studies relevant to your

personal development at work. It should also provide you with examples which can beused in your examination answers.


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And finally

We hope you enjoy your studies and find them useful not just for preparing for theexamination, but also in understanding the modern world of business and in developing inyour own job. We wish you every success in your studies and in the examination for thismodule.

The Association of Business Executives

September 2008


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SAD

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6. Explain the main modelling techniques employed in SSADM andemploy these techniques to solve problems

6.1 Explain the concept of modelling and distinguish between logicaland physical models

6.2 Identify the main process, data and event models employed in

SSADM and explain their purpose6.3 Analyse small case studies and construct appropriate process,

data and event models7. Compare and contrast alternative approaches to information

systems development

7.1 Compare and contrast the hard and soft approaches toinformation systems development

7.2 Discuss the main features of alternative approaches such asRapid Application Development (RAD), Joint Application

Development (JAD) and Object-oriented Design (OOD)7.3 Explain the role of Computer Assisted Software Engineering

(CASE) tools in system development7.4 Find solutions for the design of Internet-based systems

8. Explain the importance of standards in SAD

8.1 Discuss the role and scope of standards in projects8.2 Identify the main components of documentation in a systems

project8.3 Develop system documentation using a current standard

9. Create plans for the implementation of operational systems

9.1 Demonstrate the use of alternative techniques for monitoringand controlling the progress of projects

9.2 Compare alternative strategies for performing the changeover toa new system

9.3 Examine and report a projects degree of success

10. Manage systems problems relating to security and long term

support

10.1 Identify the security requirements of a system and introduceappropriate procedures and precautions

10.2 Develop procedures to manage the maintenance aspects of anoperational system

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Assessment Criteria:

Assessment method: written examination

Length of examination: three hours

Candidates should answer four questions from a choice of eight, eachquestion carrying equal marks

Recommended Reading

ABE,ABE Study Manual Systems Analysis, ABE

Avison D E, Fitzgerald G, Information Systems Development(2002), McGraw-HillEducationISBN: 0077096266

Yeates D, Cadle J, Wakefield T, Systems Analysis and Design (2003),Pearson Higher EducationISBN: 0273655361

ABE, ABE Study Manual Systems Analysis and Design, ABE

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1

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Study Unit 1

Information and Systems

Contents Page

A. Information and Data 3

B. Information Needs 3

Role of Managers 3

How Much Detail is Needed? 4

Timeliness 4

Accuracy 4Rarity 5

Quality of Information 5

C. Types of Information 5

Operating Information 6

Management Information 6

Trigger Information 7

Background Information 7

D. Management Information 8

Regular Reports 8

On-Demand Reports 8

Ad-Hoc Reports 8

Exception Reports 9

Analyses 9

Forecasting 9

E. Systems Theory 10

System Properties 10

Probabilistic and Deterministic 11

Open and Closed 11

Quantitative and Qualitative 12

(Continued over)


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2 Information and Systems

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F. Objectives of a System 12

Necessity for an Overriding Objective 12

Objectives of a Wider Context 12

How Objectives are Created 13

G. Information Systems 13

H. Types of Information System 14

Transaction Processing Systems 15

Office Systems 15

Knowledge Work Systems 15

Management Information Systems 15

Decision Support Systems 15

Executive Support Systems 15


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Information and Systems 3

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A. INFORMATION AND DATA

It is important that you understand the difference between information and data.

Data is raw facts; for example, a group of figures, a list of names and such like. By itself,data tells us nothing. Consider the following numbers:

212 263 189 220

In that form, the numbers could have a thousand different meanings. But if we add to thefigures:

212 263 189 220

We can now see that they are monetary values.

If we add some dates:

January = 212

February = 263

March = 189

April = 220

Now we see that they demonstrate some kind of trend.

Alternatively:

212 screws, 263 brackets, 189 plugs, 220 bolts.

In this version we see that they are items on an order form.

We could rearrange the figures, we could add them up, find their differences, join themtogether and so on. Only when the figures have been further processed do they tell ussomething. They then convey information.

Information is raw data processed so as to convey a new meaning.

Theoretically, once we learn that new meaning, the information reverts to data, but in practicewe continue to regard it as information.

B. INFORMATION NEEDS

In organisations, information is required as the basis of taking action essentially bymanagers.

Role of Managers

Managers normally have two roles

decision maker; and

controller.

Stated simply, the processes involved in these roles is for managers to make a decision,check the outcome and either confirm or modify the decision in the light of events. This is astandard control process, involving five stages:

(a) Establish a plan.

(b) Record the plan.

(c) Implement the plan.

(d) Compare actual performance with the plan.


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(e) Evaluate and decide further action.

You will readily see that information is needed at (a) in order to establish the plan, and at (d)to see how things are working out. There is a constant flow of information.

How Much Detail is Needed?

Now that we understand what information is, it is appropriate to gain further understanding ofthis information.

First of all, what level of detail is needed? Clearly this depends on the recipient or receiver ofthe information. For example, the shop manager may need the daily sales total, whereasarea office may only need weekly totals. On the other hand, head office may only beinterested in monthly totals. We should only provide as much information as is actuallyrequired.

"The more detail, the more information" is not necessarily true. Were head office providedwith daily totals by each store, the "information" would simply be a mass of data requiringfurther processing before becoming information.

Therefore, although a mass of data is needed from which to draw the information, the detailbeing passed to managers should be no more than they require.

Information must be relevant to the purpose for which it is being used. Users should beprovided with the minimum of information which will satisfy their needs. This is quite easy toachieve with computers, and information reports can be formatted according to individualuser requirements.

Timeliness

"Information should be available instantly." This is possibly true at operating level, where thetime-steps can be very short for example, spoilage rate information on a production lineneeds to be readily available in order to check immediately on any deficiency as it arises. At

managerial level, however, there is usually a longer thinking and decision time available, andso the need for immediate information is not necessarily valid.

The aim must be to provide timely information that is, information at the time it is required.We can therefore say that information must be provided within a time-scale which enables itto be used effectively by management.

Accuracy

A high level of accuracy is usually achieved only at a high cost. Managers must be madeaware of the cost impact if they specify very accurate information needs. Often slightly lessaccurate but sufficient information can be provided at a greatly reduced cost and it may alsobe more up-to-date.

Note the difference between accuracy and precision. Sales figures could be computed tothe nearest penny, pound or thousand pounds i.e. calculated to different levels of precision.However, if the data has been incorrectly entered, or the calculations carried out incorrectly,the resulting total will be inaccurate (wrong). Another type of inaccuracy is whenapproximate sales figures are collected because it would be much later in the month beforeexact figures were available. It is here that a compromise is made between accuracy andtimeliness.

This compromise is important and we can think of a further example involving quotations fora proposed new product. Imagine the situation being one where the quotations are urgentlyrequired and yet 100% of supporting data is not known. In such cases, a 5% error margin

may well be acceptable as a compromise in facilitating the progress of the quotations to thecustomer.


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Rarity

Exception reporting draws the attention of users to changes in the situation. It avoids theneed for managers to wade through long lists, looking for the one vital piece of information.

But who decides what is exceptional and how do they decide? When a system is beingdesigned, careful thought must be given to this aspect and the ability to alter the parameterswhich denote exceptions should be built into the system.

Management by exception is an important approach which, if used correctly, can greatlyincrease the effectiveness of management. What criteria constitute "exceptions" must beregularly reviewed, so that they do not become outdated and thereby provide inaccuratereporting for consideration and actioning by management.

Quality of Information

Quality information needs to be relevant, reliable and robust.

Relevant means it is pertinent to the recipient, who will then operate more effectivelywith the information than without it.

Reliable means that the information is timely, accurate and verifiable.

Robust means that the information will stand the test of time and failures of handlingwhether human, system or organisational.

C. TYPES OF INFORMATION

All businesses can be categorised into three main areas of operation:

Figure 1.1

As we saw in Section B previously, all the information, at whatever level, should be:

relevant to requirements

at an acceptable level of accuracy

up-to-date and timely.

Looking at information from a managerial viewpoint, we have the following.

Strategic Level(Directors)

Tactical Level(Managers)

Operational Level(Supervisors)

Feedback

Policyinstructions


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(a) At the operational level, the shop-floor supervisory staff receive daily and weeklyoperational requirements such as order sheets, product changes and so on. Theyprovide returns of orders filled, stock levels, spare capacity, manpower used andrequired and so on.

(b) Such information as above is used in summary form by managers at the tactical level in

the actioning of reports on performance, budget versus actual and so on.(c) At the strategic (director) level, information is much more global, having been highly

summarised. It is at this level that policy making decisions, short- and long-term, aretaken and passed down to the tactical level for actioning by the management.

In Figure 1.1, note how policies are passed down but their interpretation in terms ofactioning is left to the management to administer. Feedback is then passed back upthe strata originating in the operational level and finally, after much processing andrefining, reaching the strategic level for overall review.

It is important that you are constantly aware that the above three information levels are notdiscrete. They all overlap, especially in smaller organisations where directors and managersmay be the same people and where managers take a more "hands on" approach tooperational matters.

It will also be useful for us to look more closely at each of these categorisations from aninformation viewpoint.

Operating Information

Operating information is used to instruct the employees of the business to ensure that theyall know what is required of them. Despatch instructions to the warehouse, for example,state what is to be despatched and where it is to be sent.

Operating information which can also be called routine information contains the facts ofwhat has been done, to provide a history of the actions carried out. A stores issue note

records the fact that a quantity of raw materials has been given out to be used in production.

This type of information can flow to and from the outside world orders received fromcustomers, invoices sent to customers, or bank statements.

Without this information, the business could not operate. It is often termed "paperwork" sincemost operating information is presented in the form of paper documents.

When companies start to use computerised data processing, it is normally used first for theproduction of operating information. However, microcomputers are beginning to change this,particularly in very small companies where the amount of paperwork to be handled isrelatively small and often very varied. In such circumstances, management techniques suchas the use of spreadsheets often play a prominent role in the computer utilisation. Word

processing also tends to dominate the small business area because of its universalapplication.

Management Information

All three categories of information can be collectively seen as management information.

(a) Firstly, we have those decisions associated with the day-to-day running of thebusiness:

"What action must be taken to bring the sales level up to the budget estimate?"

"Will overtime be needed to complete a job?"

Most of these decisions are taken by junior levels of management for example, bysupervisors and usually require that the information contains very detailed facts about


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the activities for which the manager is responsible. This information will come in theform of reports giving detailed summaries and analyses of the current situation.

This type of information is often categorised as operational information.

(b) Secondly, middle management is responsible for the overall running of the business ona week-to-week and month-to-month basis.

They must compare actual expenditure and sales with the targets provided by seniormanagement, and require information to back up explanations of any divergences fromthe budgeted figures. They must also prepare the terms of reference to which juniormanagement is to operate.

We can thus say that the information requirements of middle management are not sodetailed, but they are wider-ranging they will need to know about the outside world,as well as the progress of the business itself.

This type of information is generally categorised as tactical information.

(c) Finally, the senior management needs to plan into the future, often as far as five yearsahead, and possibly further. They provide a framework for middle management bydefining the policies to be followed and setting yearly budgets and targets. Theirinformation requirements are therefore more general and each decision they take willhave far-reaching effects.

This type of information is generally categorised as strategic information.

An organisation needs to collect data about items not immediately related to therunning of the organisation i.e. future prices of raw materials, competitive products,personnel skills, national statistics, new processes, new equipment, etc. Aconsiderable volume of this data is to be found within any organisation and exists inmany different forms. This data is used in considering strategy in medium- to long-termplans.

All the categories of information also include two sub-types: trigger information andbackground information.

Trigger Information

As its name implies, this triggers some action. In the case of operational information it isusually an instruction which is to be carried out, for example a job card which instructs amachine operator to make a particular item; or a request which requires a decision before anaction is carried out, for example an order from a customer whose credit limit may needchecking before the order is met.

A trigger for management could be a report indicating that production was lower thanexpected, and the manager would have to decide how the situation was to be rectified.

A trigger for the directors may be national statistics such as the exchange rates or acompetitor's actions in introducing a new product. A corporate response will be required.

Background Information

This gives additional knowledge when trigger information is received. In the case of thecustomer order above, the clerk who checked the order would refer to the customersaccount to find the credit limit and the current balance. These last two items are backgroundinformation for the clerk.

In the case of the lower production report, relevant background information could beknowledge of seasonal demand cycles, or of a technical interruption to production which has

been corrected.


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In the case of the introduction of a new competing product, background information could beknowledge of the competing companys strengths or weaknesses.

D. MANAGEMENT INFORMATION

We have looked at information needs in the context of management decision-making. Thecomputerised system that provides the relevant information is known as a ManagementInformation System or simply as MIS.

We study these in much more detail later in the unit and elsewhere in the course

Whilst some of the information may be obtained directly from a screen display, as a result ofan enquiry, most of it will be presented in the form of reports. Managers are now, however,beginning to access information in a third way by extracting it from the main computer filesand then manipulating it themselves, using a computer package such as a spreadsheetrunning on a personal computer or workstation. Various types of report are generated bysuch a system to help managers make decisions.

Regular Reports

These are the daily, weekly, monthly, annual reports produced automatically by the computersystem. The problem here is to make sure that the information presented is relevant to therecipient and that regular reports do not have too wide a circulation list.

On-Demand Reports

The term "on demand" can be used in two ways:

(a) Particular managers may request a copy of a regular report only when they themselveswant one.

(b) A standard report can be requested at a time when it is not normally produced; forexample, if aged debtor reports are normally produced at the end of each month, acredit controller could request one in the middle of the month.

It is more efficient to provide information for just those people who require it but, especially inlarge organisations, on-demand reporting requires an organised response system.Otherwise, managers will become frustrated if they cannot get the requested informationquickly when they do need it.

Ad-Hoc Reports

Managers sometimes require items of information in a form which has not been specifiedwithin the computer system. If the data is not available within the computer system then the

request cannot be met. For example, if a Sales Director asks for monthly sales of a productfor the past year but the computer holds only sales this month and sales for the year, the onlymethod of obtaining the information is to go back to monthly sales analyses kept as hardcopy providing these exist in the form required.

Even if the data is within the computer system, extracting it may be a complicated processwhich cannot be carried out in the short time managers usually allow between issuing therequest and requiring the output. To some extent, the links between main systems andspreadsheet packages, now quite common, make it easier to satisfy these requests.However, one way of coping with ad hoc reports is to try to foresee what might be requiredand to incorporate them as on-demand reports when the system is built.

Modern computer systems are now increasingly overcoming this problem by using report

generators. Such programs allow managers to specify the format in which they want data tobe printed out and they also allow for sub-totals, totals and other calculations to be


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incorporated therein. Provided that data is held on the computer system, the specified reportextracts it quickly and accurately in the format specified. Such reports can either be used asthey are or incorporated into word-processed reports of a longer nature. Whichever reasontriggers the request, properly used they can provide a cost-effective means of enabling adhoc reports, user specified, to be produced.

In many circumstances the ad hoc report tends to become a regular supplement to thestandard report pending the next system revision. This would then establish its justificationas being worthwhile of inclusion as a standard report and the system would be amendedaccordingly.

Exception Reports

Exception reporting was mentioned earlier. An exception report could also be a regularreport, for example a weekly report showing all those stock items with orders overdue bymore than a week.

Analyses

An analysis summarises information in a particular way. For example, sales analyses can besummaries by:

(a) Product

Which products were bought by which customers? The analysis could be summarisedat the product group level or give information down to individual products.

(b) Customers

Which customers (type of customer) bought which products?

(c) Region

Which geographic (or sales) region bought which products?

Data held in a computer can be analysed in so many different ways that it is important thatdesigners consider what will really be useful to their particular company. The ability to varythe grouping and selection criteria is also useful.

When packages are produced, sales analysis is one of the areas where it is often possible tocustomise the reports which are produced. This is because each company has its ownindividual requirements.

When deciding upon the depth of sales or other analyses, it is important to remember thatstorage has a cost and that this cost must be compared with the benefits of such storage.Despite storage having increasingly large capacity and its costs reducing greatly, thiscompromise remains valid today.

Forecasting

Many packages now include a forecasting module, but it is important that managers knowhow these forecasts are obtained, since there are a variety of techniques which can be used.Strictly speaking, information based on historical data projected into the future is a prediction,whilst forecasts are based on subjective judgements as to the effect of various factors. Manysales forecasting systems start with historical predictions.


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E. SYSTEMS THEORY

A dictionary definition of "system" is:

"Anything formed of parts placed together or adjusted into a regular and connected whole."

It would be worthwhile if you were to pause at this point and think of some of the systems youare familiar with.

You may have thought of:

central heating system

a motor car

road/railway system

administrative system

government system

management system

and so on.

System Properties

Systems receive input and produce output.

Systems consist of sub-systems which are themselves systems performing some function onbehalf of the larger system. A fully integrated system consists of sub-systems, each of whichhas, as input, the output of another sub-system so that all the sub-systems together fulfil theoverall objective of the whole system.

A system must have a boundary; outside the boundary is the environment. Theenvironment of a computer system includes any people or business activities which interactwith it, the sources of the data which forms its input and the recipients of the information itprovides.

The art of systems analysis is being able to define system boundaries to decide whichparts should be included within a particular study, so that a logical and convenient model canbe prepared.

Another definition of system is "the method by which an individual, organisation ormechanism accomplishes the tasks necessary to achieve its objectives". The method usedwill be made up of a number of related procedures, and in a large system there may begroups of procedures called sub-systems. Figure 1.2 shows a business system consistingof four main sub-systems, each of which can be divided as shown for accounting into a

number of smaller sub-systems.A system can thus be thought of as hierarchical, and this hierarchical nature extends bothways, in that the system being described can also be looked at as being a sub-system of alarger or wider system. Staying with our accounting example, a sales ledger system iscomposed of a number of subsections, whilst itself being a sub-system of the totalaccounting system of the organisation.


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Figure 1.2

THE BUSINESS SYSTEM

ACCOUNTING MARKETING PRODUCTION PERSONNEL

Sales

Purchasing

Payroll

Fixed Costs

Profit and LossAccounts

Probabilistic and Deterministic

Consider a slot machine. Here you place your coin in the machine and, provided themachine is stocked, the required item will be delivered automatically. The outcome is

completely predictable; a slot machine is an example of a deterministic system. Wheneverwe take a particular action, the result or resulting action will invariably be the same, providingthat the system is working correctly. Every step in the system has this feature and so thetotal system is deterministic in nature.

A computer can be considered to be a deterministic system since it automatically follows theseries of instructions it has been given. At least this is true for traditional computer systems,which includes the vast majority of those currently in use and certainly all those used for dataprocessing.

Alternatively there are probabilistic systems whose predictability is less than that ofdeterministic systems. If, instead of always getting an item out of a slot machine, yousometimes got nothing for example, from a fruit machine or some other gambling device

then this system would be probabilistic. Stated simply, we can never be certain of how sucha system will work, but we can assume that a specific action will take place, based on ourprevious experience or knowledge.

An example of a probabilistic system is a game of cards or the pricing system of anorganisation.

Open and Closed

When a system is isolated from its surrounding environment it is a closed system. When asystem responds to input from its environment and provides output to the environment, it isan open system. The same system can be seen as closed or open when viewed fromdifferent perspectives. For example, a payroll system is closed when viewed from an

organisational position, but is open when seen from inside the payroll section.


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Quantitative and Qualitative

A quantitative system will process and output actual values. All financial systems arequantitative.

A qualitative system processes and outputs less measurable quantities such as "a betterservice to clients".

F. OBJECTIVES OF A SYSTEM

Objectives are the goals towards which a system is working. In an organisation the overallobjectives are seen differently in the separate departments, each of which tends to have itsown objectives. For example, with inventory, Marketing wants to be able to supply thecomplete range of products whenever customer demand occurs; Production wants tomanufacture products in long runs of each product to reduce set-up costs, etc.; and

Accounting wants to keep stocks to a minimum.

Decisions selecting between conflicting objectives have to be made and once made they

become policies and lower level decision-making will have to be made within the context ofcompany policies. If, for example, it is company policy to buy computers from one particularsupplier, then a proposal for a computer system will need to be designed round the modelsoffered in a given range, unless a very good case can be made for using a machine from acompetitor.

Necessity for an Overriding Objective

By definition, every system must have an objective. It is essential that an objective isdecided upon even before the system is designed. At this stage it is likely that a number ofconflicting objectives will be considered. For example, when discussing the setting up of aproduction line, the following objectives may be amongst those considered:

the complete safety of the line.

the best environment for the production line.

the best equipped line to produce a better quality product.

the most efficient line in terms of cost per unit of output.

No doubt there will be other objectives, but you can see that many of them will be in conflict.This conflict of objectives is a characteristic of all systems. It is essential for all objectives tobe considered and an objective established that is a compromise between all those inconflict.

The overall objective that has been established for a system must be one that can be

achieved. Although the objective may at times seem difficult or nearly impossible, it is ofprime importance that in the long run it is achievable.

Objectives of a Wider Context

We have said that individual systems form part of a larger system. It is essential whensetting out systems objectives that account is taken of the objectives of the next highersystem.

It is better if the objectives of the higher systems are known before those of the sub-systemsare established. The communication of the objectives from the higher to the lower systems isof great importance.


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How Objectives are Created

The overall objective of a system is created firstly by listing all possible objectives. Many ofthese will be in open conflict and it is therefore necessary to weight, in order of importance,the objectives so far specified.

This list will have been formulated by consulting the interested parties. When an overallobjective has been decided upon, it is necessary to "sell" it to those parties whose ideaswere in conflict at the earlier stage. Perhaps at this stage minor alterations will be made afterfurther consultations.

G. INFORMATION SYSTEMS

Let us consider a motor car as an example of a system. Its input is fuel and its outputs areexhaust gases and motion. Its component parts include engine, body, gearbox, brakes, etc.or in terms of sub-systems transmission system, hydraulic system, electrical system etc.The boundary is the car body

A lot of this course will be concerned with analysing a system by breaking it down into itscomponent parts. The idea that a system may be made up of sub-systems is crucial to thewhole subject of systems analysis.

The motor car is an example of a physical system. Let us now get a little closer to the mainmaterial of this course. There is a particular type of system called an information system.This is a system which processes data and produces information. We have alreadytouched on this in previous sections of this unit.

The inputs and outputs to and from an information system are not physical things like food orfuel, but are items of data and information, numbers and words and characters. Theamazing thing is that the same principles apply to an information system as to the othersystems we have mentioned. The component parts of an information system are not

physical things like the gearbox or the brakes, but are processes which are performed onthe data to transform it.

People often talk about information being the most valuable asset a company has. Aninformation system is at the heart of this statement. Note that we are not necessarily talkingabout a computer system - an information system can be entirely manual. However,nowadays, information systems are increasingly implemented on computers as the amountand nature of data and information is getting bigger and more complex.

Information systems provide information to managers and whoever else requires it. It isdifficult to classify information systems as deterministic or probabilistic. They areprogrammable (i.e. can be computerised) and thus appear deterministic. From the userviewpoint, however, there may sometimes be no satisfactory output, thus making themappear probabilistic.

In the same way, they can be seen as both open and closed. However, as we shall alwayswant information systems to evolve, they are primarily open.

They do need to be quantitative though. The user needs concrete information on which tobase decisions.

An efficient and effective information system will always give:

the right information

to the right person

at the right time

at the right cost.


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(a) The Right Information

The information should be in detail appropriate to the recipient detailed plant-by-plantfigures for plant and works managers and only the summarised variances for themanaging directors (although they can always get supporting information if they wantit). Beware, however, of being too summary orientated: it is essential to measure what

is happening from time to time, otherwise it is easy to become a summary expertwithout knowing any real facts. The information should be relevant.

However, a flow of information across specialised barriers is essential, otherwisemanagers get too shut up in their own worlds and may forget for whom they areworking and what effect they have on the company's operations. It can be dangerousto feed summaries to persons other than the specialist who is in control, for it can leadto a lot of unfounded pessimism at bad figures or joy at good ones, when only theexpert knows how bad is bad and how good is good!

(b) To the Right Person

This depends greatly on who set the budget and how. In the ideal situation, informationis fed to the lowest possible point in the company hierarchy at which the recipient ishappy to accept responsibility for the figures and do something if they are wrong.

(c) At the Right Time

In principle, the right time is "not too early, not too late", so that the best form ofcorrective action can be taken. There is an obvious difference between statistics onthe temperature of a chicken run, where only several minutes outside certaintemperature limits can cause death to the birds, and statistics on aviation insurance(figures more than once every six months are useless).

(d) At the Right Cost

There is no point in spending much time and money getting figures accurate to four

percentage points if equally appropriate controlling action could have been taken on 5%. This quest for accuracy usually results in the information arriving too late to be ofany use. It is a natural feature of industry to specify the tolerances to which anyproduct should be made. This parallel should be extended to information:accountants, for instance, have to be told what information is required and howaccurate it has to be.

H. TYPES OF INFORMATION SYSTEM

If you look back to Section C of this unit, you can see that organisations have three mainlevels of operation. These are the operational level, the tactical level and the strategic level.

Each level requires different types of information in order to function. As a result, each leveltends to be associated with a different type of information system.

There are a number of ways of categorising the types of information system. Movingupwards from the operational to the tactical level, the following types of information systemsare often listed:

Transaction Processing Systems

Office Systems

Knowledge Work Systems

Management Information Systems

Decision Support Systems Executive Support Systems


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Transaction Processing Systems

Transaction Processing Systems are the basic operational level systems such as orderprocessing, payroll, stock control. Their input consists of basic transactions such as orders,hours worked, number of parts received, and their outputs are detailed reports, lists andsummaries.

Office Systems

Office Systems are now a way of life in organisations. They are used by everyone andinclude word processing, spreadsheets, databases, email. They can be classified asknowledge-level systems.

Knowledge Work Systems

Knowledge Work Systems are again often classified at the knowledge level. They are usedby technical and professional staff, and include modelling and simulation software, computer-aided design, sophisticated desk-top publishing applications and other technically-orientedsystems.

Management Information Systems

Management Information Systems tend to be used by middle managers. They take thesummary transaction data from Transaction Processing Systems as input and producesummary and exception reports. This type of information system was described in moredetail in Section D of this unit.

Decision Support Systems

Decision Support Systems are a very important tool. They are used extensively byprofessionals and staff managers, but can be used at all levels. A spreadsheet can be usedas a decision support system. As the name suggests, they are used to provide information tohelp people make decisions. Input can range from low-volume data to very large databaseswhich can then be analysed using simulations and statistics. The user can interact with thesystem to see where various paths may lead.

Executive Support Systems

Executive Support Systems are not as specific as the other types of system. ExecutiveSupport Systems are used by senior managers and they address the strategic level of anorganisation. They use internal data produced as output from each of the other types ofinformation system, but they also use external data about the stock market, competitors,economic trends, etc. They help with strategic questions like "Are we selling the rightproducts?", "How should we go about raising cash?". They use sophisticated graphics to

present information from multiple sources to senior managers.


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Study Unit 2

The Systems Development Life Cycle

Contents Page

Introduction 18

A. The SDLC 18

Feasibility Study 19

Systems Analysis 19

System Design 20

System Construction 20Systems Implementation 20

System Maintenance and Review 20

B. The Waterfall Model 21

C. Advantages of the SDLC 22

D. Disadvantages of the SDLC 23

E. Conclusion 23


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INTRODUCTION

This study unit sets the scene for the units which follow by considering the SystemsDevelopment Life Cycle SDLC for short.

Developing an information system is usually a large project. All projects need to be planned

and managed, and it does not matter whether you are building a bridge, planning a weddingor developing an information system the same general rules apply. You need to knowwhere to begin, where to end and what steps to undertake along the way. The SDLC showsthe main activities normally associated with information systems development. It showswhere to start, what to do next and where to end. Having said that, it is a cycle so it neverreally ends.

As you work through later units, you will see that there are, in fact, a number of ways in whichsystems are developed, using different methodologies and techniques. The SDLC has beenaround since the early 1970s and has a number of strengths and weaknesses. Most of theother approaches were developed to overcome these weaknesses, but the SDLC is reallythe starting point for all of them. It is a highly logical and structured concept and, in this

course, it will be used as a means of introducing the various methodologies and techniques.

A. THE SDLC

There are several variants of the SDLC, but the basic principles are the same. Systemsdevelopment is divided into phases and you will see different diagrams which show betweenfour and over twenty phases.

Figure 2.1 shows a typical diagram of the basic SDLC, and, as you can see, the cycleconsists of 6 distinct phases:

Feasibility Study

Systems Analysis

System Design

System Construction

Systems Implementation

Systems Maintenance and Review

This is a highly structured approach and implies that one phase cannot start until theprevious one ends. Each phase has some sort of deliverable as an output which, in turn,acts as an input to the next phase. A brief description of each phase now follows.


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Figure 2.1: The Basic SDLC

Feasibility Study

Before any project can start in earnest, it is essential to find out whether it is feasible or not.There are a number of categories of feasibility and these will be explored in the next unit, butbasically a feasibility study will look at technical, personnel and cost issues and examinedifferent ways in which the system can be developed. For example can the system bedeveloped in-house or will outsourcing be required, does the organisation have thenecessary technical resources and expertise to undertake the project, will the system be offinancial benefit to the organisation and is the money available to develop it?

The output from this phase is a feasibility report, which summarises the study and makesrecommendations about the way forward.

Systems Analysis

Once the feasibility study has confirmed that the system can and should be developed, thenext phase consists of a detailed investigation of the requirements of the system, invariablyinvolving extensive consultation with the users of the system.

If the new system is to replace an old one, then it is normal to study the existing system indepth so that its objectives, outputs and the exact way in which it works can be understood,as well as identifying any problems associated with it so that these are not repeated. At thesame time, it is necessary to find out what new features and functionality should be includedin the new system.

The output from this phase is a requirements specification. Many analysts view this phaseas the most important. It is all very well building a sophisticated system which looks goodand produces impressive output, but if these outputs are not what the users want, the systemis a waste of time.

Feasibility Study

Systems Analysis

System Design

System Construction


System Maintenance and Review


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System Design

This phase takes the requirements specification and converts it into a system designspecification. This involves the design of inputs, outputs, databases, computer programsand user interfaces.

The design phase is normally split into logical and physical design. Logical designconcentrates on the business aspects of the system and is theoretically independent of anyhardware or software. Physical design takes the logical design specification and applies it tothe implementation environment. Most often the choice of programming language anddatabase is already decided and these technologies are taken into account in physicaldesign.

The system design specification contains all the detail required for the system builders toconstruct the system.

System Construction

This phase is where the system is actually built. The system specifications are turned into a

working system by writing, testing and, in due course, documenting the programs which willmake up the whole system. Once the individual programs have been tested, the wholesystem needs to be put together and tested as a whole. This whole phase requiresextensive user involvement.

The output from this phase consists of detailed program and file specifications which, intotal, describe exactly how the new system works.


The objective of this phase is to produce a fully functioning and documented system. Itinvolves training users, transferring data from the old system to the new and actually puttingthe new system into operation "going live". There are a number of different approaches to

this, as we shall see later in the course.A final system evaluation will also need to be performed to make sure the system worksaccording to expectations.

System Maintenance and Review

During the life of a system, continual review and maintenance will need to be performed inorder to maintain its functionality. For example, new requirements may need to beimplemented and errors in the system need to be rectified. Such maintenance is really arepetition of the other phases of the life cycle as a new requirement or a fix for an errorneeds to be analysed, designed and implemented.

Eventually all systems become outdated and need to be replaced, so the cycle starts again,with the way in which the old system is operating and the requirements which now applyforming the backdrop to a new feasibility study to examine whether a new system should bedeveloped.


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B. THE WATERFALL MODEL

The basic SDLC in Figure 2.1 implies a purely linear approach in that one phase finishesbefore another one starts and there is no going back. In practice, of course, this isunrealistic. When working though a phase, it is often the case that something does not work

out as planned or that there is an error or omission in the previous phase. It is, therefore,necessary to go back and modify the previous phase.

So, there is an iterative nature to the SDLC, and this is shown in Figure 2.2. This approachis often called the Waterfall Model, and the dotted lines on the diagram show the interactionbetween phases, with the possibility of returning to a previous phase to make adjustmentsalways available.

Figure 2.2: The Waterfall Model

As already mentioned, there a many different methodologies and techniques used indeveloping systems. SSADM, for example, is a structured methodology which follows theSDLC very closely, and we shall examine this in later units. In object-oriented systems

development, the boundary between the analysis and design phases is often indistinct. Inthe prototyping approach, analysis, design and construction are all often done together.

SystemMaintenance and

Review

FeasibilityStudy

SystemsAnalysis

SystemDesign

SystemConstruction

SystemsImplementation


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Again, you will see this in later units. The techniques used in each phase also differ.Structured methods separate processes and data and model them using different techniques.Processes are modelled by data flow diagrams and data by entity relationship diagrams. Inobject-oriented methods, processes and data are not separate, but are combined intosomething called an object.

However, whatever approach is adopted and whatever techniques are used, any systemdevelopment needs to go through feasibility, analysis, design, construction, implementation,maintenance and review. It is the way this is done that differs.

The SDLC is often termed the "conventional" or "traditional" approach to systems analysisand design and although it is rarely used in its entirety nowadays, its influence is veryapparent and many of its features play a prominent part in the various approaches whichabound today.

C. ADVANTAGES OF THE SDLC

Whatever the drawbacks of the SDLC, it was highly successful in the 1980s and 1990s. Itsmain advantages are that it lends itself to project management techniques, produces well-documented systems and uses tried and tested techniques.

Project management

Breaking down a project into phases has distinct advantages in that each stage can bespecified, planned and evaluated before moving on to the next planned stage. Thisenables the whole project to be closely managed, and is the same approachextensively used in engineering projects such as building a bridge, and the sameprinciples apply.

In some structured approaches such as SSADM, each phase is further sub-divided intostages, stages into steps, and steps into tasks. Each task, step, stage and phase can

then be estimated for duration and cost, staff can be allocated to them, and then theycan be monitored and adjusted accordingly. With today's project managementsoftware this becomes quite straightforward.

As each phase has a start and end point, this provides opportunities for qualityassurance of the outputs before the next phase is allowed to start. It is particularlyrelevant to large projects such as those involving government departments and it is nosurprise therefore that SSADM originated in the UK Treasury!

Documentation

Because of the benefits of project management, the SDLC tends to be associated withthorough documentation. Each stage has its own documentation standards and these

make the quality assurance processes much easier. CASE tools are available whichcan be used to produce all of the diagrams and forms and integrate them into a projectrepository.

Tried and Tested Techniques

The SDLC tends to be associated with structured methodologies such as SSADM. Notonly do these methodologies break a project down into manageable parts, they alsoprovide tried and tested techniques to use along the way. Data flow diagrams, entityrelationship diagrams and entity life histories are all widely accepted techniques whichhave been used in thousands of projects.


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D. DISADVANTAGES OF THE SDLC

In the 1980s and 1990s, technology, programming techniques and the demands oforganisations advanced to such an extent that the SDLC became unwieldy. It becameregarded as inflexible, narrow in focus, not responsive enough to the needs of organisations,

and using old-fashioned techniques. Projects took too long to develop and were frequentlyover-budget.

Inflexibility

Because the SDLC has distinct, sequential phases it was regarded as inflexible,especially for smaller systems. With the appearance of the Internet in the 1990s,businesses started to use information systems for competitive advantage rather thansimply for automating background business processes. The demand for systems to bedeveloped quickly became a priority and the SDLC approach was just too rigid andinflexible.

Narrow focus

Again, as business philosophy developed in the 1990s, information systems becameregarded as tools to support business objectives, rather than objectives in their ownright. The SDLC tended to be used to develop low level operational systems andlargely ignored the needs of middle and senior management.

Old-fashioned techniques

The SDLC is associated with structured techniques and many of these have beenfound to be inappropriate for today's modern systems, particularly Internet basedsystems. Object-oriented techniques have now largely superseded structuredtechniques, especially when modelling systems processes.

Time and cost overruns

Although this is a criticism often levelled at the SDLC, it is common in many largeprojects. You often hear of government projects which cost many times more thanoriginally estimated and take much longer than originally planned. It is as true of majorbuilding works as of information systems. In reality, this is basically down to poorproject management, rather than anything intrinsic to the development process itself.However, as the SDLC was used on so many large-scale developments which ran intotrouble, the SDLC became tarnished with a reputation for inefficiency.

E. CONCLUSION

The SDLC has been around since the early 1970s and has been tremendously influential in

information systems development. For the first time, it provided a structure to thedevelopment of information systems and was used extensively in the 1980s and 1990s.

As technology and the demands of business have advanced, the SDLC has basically servedits time. It has given rise to many other approaches which attempt to overcome some of theproblems associated with the SDLC. However, many of the principles behind it still apply.Many of the study units which follow use the SDLC as the basis for introducing new conceptsand techniques.

There is nothing intrinsically wrong with the SDLC and many of the problems associated withit still remain in other approaches. Projects still overrun and come in over-budget. However,it is true that the SDLC is often not flexible or responsive enough to cope with today's rapidlychanging business demands, where systems need to be built and implemented quickly inorder to maintain competitive advantage.


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Study Unit 3

System Specification

Contents Page

Introduction 27

A. The Development Life Cycle 27

Key Points and their Output 29

The Importance of Documentation 30

B. Statement of Requirements 30

System Selection 31

The System Environment 32

The Initial Study 32

User Involvement 33

C. The Personnel Involved 33

The Computer Professionals 33

Users as Clients 35

Computer and User Staff Relations 37

D. Systems Investigation 39

The Scope of Fact Finding 39

Interviewing 42

Observation 43

Questionnaires 44

Existing Written Material 45

Sampling 46

E. The Feasibility or Initial Study 47

Aims 47

Determining the Main Requirements of the System 47

Considering Alternatives 49

Cost/Benefit Analysis 49

The Report 51

(Continued over)


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F. Requirements Specification 51

G. Using Consultants 52


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System Specification 27

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INTRODUCTION

You should now have a general picture of the type of methodologies used for systemdevelopment. There is a wide choice, though in practice, each organisation will have afavoured or preferred approach which has evolved through the experience of the systems

manager and his or her predecessors, the nature of the organisation and the environment inwhich it operates. It is also important to be aware of the whole system into which the sub-system under development will fit, even if the sub-system is extremely large itself.Remember, few systems exist in isolation.

Whatever methodology or approach is used, the system must undergo some definitionprocess. This is an important topic, so we shall start our study of the development process inthe very first project stages and examine the specification of a system through the initialinvestigation and feasibility study.

First of all, though, we shall briefly review the whole development process.

A. THE DEVELOPMENT LIFE CYCLEWe have already looked at the life-cycle stages in an earlier unit, and saw that developmentwork should proceed in orderly steps, with the output from each step being checked againstthe definition of that step before work proceeds.

Notwithstanding this point, though, we also saw that there must be some recycling, reworkingof a previous stage in the light of subsequent work, and constant referral back to therequirements specification. In other words, it is an iterative process.

Figure 3.1 repeats the SDLC diagram from the previous unit and shows how the stages areinterrelated and how the whole cycle constantly involves referring back and going back towhat has already been done.


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Figure 3.1: System Development Life Cycle

Note that, if the system is to be provided by an outside supplier, then Figure 3.1 can bereduced, as shown in Figure 3.2. But, remember, if the supplier is providing a tailor-madesystem, the purchaser should monitor progress, since the three stages of system design,detailed design and programming will have to be carried out by the supplier and, during thesestages, there should be continuous feedback on how the work is progressing, whether anysnags have developed, how costs and time-scales are matching up to budget, etc.


Review

FeasibilityStudy

SystemsAnalysis

SystemDesign

SystemConstruction



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Figure 3.2: System Development Life Cycle (with external support)

Key Points and their Output

There are certain key points within the life cycle, for example:

Agreement of the specification of requirements (the key output of the Systems Analysisphase), which should be clear, consistent and unambiguous to users as well ascomputer specialists.

Systems testing and hand-over to the users, as the key output of the SystemsImplementation phase.

These key points must be clearly identified and the outputs associated with them need to be:

(a) specified before work on the phase starts; and

(b) agreed as having fulfilled this specification before the phase is completed.

The detailed production of specified items at each stage allows monitoring to take placeagainst the schedule of key points. This not only demonstrates progress, but it alsohighlights any areas where problems might develop. It is most important that errors are

discovered as early as possible, since their continuation into later stages can cause majorproblems, and particularly with the development of software, errors found at the operational


Review

FeasibilityStudy

System Purchase/Commission

SystemsAnalysis

Supplier:

System DesignSystem Construction

SystemSelection



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stage can cost fifty to a hundred times as much to correct as if they had been found at thedesign stage.

Key points are sometimes called milestones and it is important that their position, and whatis to be delivered at that stage, are agreed with both purchaser and supplier. (Note thatpurchaser and supplier may both be within the same company for example, a user

department and the computer department.) If the supplier is external, it is important that theactual people who will eventually be using the system are involved in its specification andacceptance.

The Importance of Documentation

Documentation should be going on in parallel with the other activities and, at least at theearly stages, documents will be the items produced as output. These will need to be referredto at later stages. For example, the requirements specification will need to be checkedagainst parts of the feasibility study and any major changes in plan discussed and agreed.This requirements specification will be the basis against which the design is checked. Thisdoes not mean that, once agreed, there can be no changes to the specification. Work

carried out at the design stage may show how improvements can be made. Thespecification, after full steering committee and user consultation, will be altered toaccommodate the improvements.

B. STATEMENT OF REQUIREMENTS

The first stage of all development cycles is a statement of requirements from the eventualuser department. As such, then, it is also known as the user requirement document andthis forms the basis on which the feasibility study will be conducted

This statement should specify what is required of the system, both functionally andfinancially. Note that it does not suggest how these requirements will be achieved. Rather, it

provides a general description of the system which has to be designed, and acts as a generalguide for the more detailed analysis and design that will come later. Three elements can beseen as key to this statement:

(a) What is the system expected to do?

This must be a precise and full statement of the objectives of the system meregeneralisations are insufficient. Wherever possible, the objectives should be givensome measure so that the success of the system, when operational, can be assessed.

(b) Who will use the system?

It is always important to identify clearly the eventual owners of the system. This islikely to be a particular user department or section and this department/section will be

responsible for accepting and approving each stage of development. The identifieddepartment/section will be the primary contact for the involvement of and consultationwith users by the development team.

(c) What is the minimum the system must do?

It is important for the user department to specify the minimum requirements. Apartfrom reinforcing ownership of the system at the outset, it also gives a better and morefocussed outline of the requirements and keeps the designer from developing an over-complex system that does as much as possible rather than just what is required.

However, this initial statement should not be merely a technical statement, but should alsoprovide a context for the new system demonstrating the effect that the system should have


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System Selection

There are series of factors which need to be taken into account in identifying which systemsshould actually be put into development:

Figure 4.2: Influencing factors in system selection

SizeRelevance/volume of

work

Philosophyof the firm

Personalinfluence

Advisoryinfluence

Supplierinfluence

Initial study

Feasibility study

We know that computers can do repetitive tasks very accurately and quickly, provided theyare given a suitable list of instructions the program. In addition, large volumes of workprovide even greater savings when carried out on computers. Therefore, processes thatcome within these parameters are top of the list for consideration. In effect, this automationof tasks can be regarded as the fundamental "building blocks" for the study.

After these initial considerations, we need to look at the future plans of the firm. How doesthe system contribute to the organisations goals? For example, if expansion is anticipated interms of output volumes, staff numbers and so on, a new computerised system may be

justified on its capacity to keep down costs without increasing staff. It is also often the casenow that new systems are at the heart of expansion plans, opening up new ways of operatingor new markets.

However, increasingly it is in the area of the provision of information that new systemsdevelopment is being concentrated. Take for example manual records systems. Thesequencing of the records does not lend itself to extracting information easily at best, itinvolves staff selectively collecting specific facts by laboriously searching through everyrecord, and at worst the information may take so long to collate that its use becomes nullified.The information is likely to be there, somewhere, but cost and time make its retrievalimpractical. Thus, the production of accurate, timely information that would either be difficultor impossible to retrieve without the speed of modern computer systems represents a majorgoal of business organisations.

A brief summary of the main types of system: Ways in which the computer can help in task or transaction processing.

Operations which involve the frequent copying of data from one source to another,particularly if complex searching and sorting is involved.

Routine work, particularly large volumes, which is carried out frequently in an identicalway.

Helping individual staff workloads are some staff experiencing "peaks" which stretchthem to their limit?

Enhancing security and accuracy are checks being omitted or non-existent becauseof the demands/limitations of the existing system?


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Areas where information is not available or available too late for it to be usedeffectively.

Ways in which the speed of response can be useful in providing a better service, forexample whereby queries are answered "immediately".

The System EnvironmentThe need for a new development will be formulated within an existing environment, and it isimportant to have an understanding of that environment at the outset.

We have already considered many of these factors, but it will be useful to look at them againfrom a different point of view under three socio-technical, environmental headings.

Economic

Economic factors centre around the expected increase in profitability and/orimprovement in both internal and external services provided.

Such improvements should be stated in actual factual values rather than "vaguegeneralisations", although there are of course categories of improvement which, bytheir nature, are difficult to place a tangible value upon.

Technical

Technical considerations can be subdivided into those which affect the firm and thosethat relate to the computer its operating constraints and environment. It is importantthat these considerations include all aspects of the new system, including the effect onold or existing systems as well as any wider implications of the new system.

Computer constraints can be said to relate to the technical demands of the systemsuch as hardware and software requirements, programming complexity, usercomplexity and training, etc.

SocialThe third consideration, social, is often very difficult to quantify because it involves suchissues as job satisfaction and industrial relations. Nevertheless, it is important toindicate in some way the expected effect in these areas.

The Initial Study

It is the initial study which is used to formulate the user requirements of the new system.

The initial study will be conducted by a small team consisting of the designated projectmanager and a senior user department manager, with input from systems analysis staff andusers and, possibly, an accountant. The actual composition of the team is not important,although it needs to have the skills in both system design and requirements specification tobe able to tease out all the implications of the proposed development.

The project manager will need to gain the confidence of the staff effected by the proposednew system in other words get the staff on his or her side. This will have several benefits,particularly in the willingness to get involved in the development process staff will feel lessthreatened by the impending changes and will give more co-operation. In particular, thepossibilities of the system should not be overstated and information provided about theoutcomes must be accurate and realistic. Raising people's expectations and then notmeeting them can demotivate staff and make them distrustful. On the other hand, if staff onthe current system are really heavily loaded, the prospect of improvements being made couldmake a great deal of difference to people's attitudes.


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User Involvement

This is another aspect that we have already noted, and we will return to it again. However, itis probably one of the most important features of modern system development, and it is, ofcourse, of particular importance at this early stage.

It is essential for the potential user of the future system to work with the system analyst fromthe very beginning. This provides clear advantages, including:

acceptance of every stage of the development;

ensuring the design meets the user needs;

making the provision of training easier as there is a user representative whounderstands the system.

Other advantages are training within user areas of development staff and establishing goodrelations between all computing staff and the users. Thus, not only do the development staffunderstand the user's requirements, but the user understands the project as well.

We shall look in more detail at the whole area of development staff and relations in the next

section, before moving on to examine the way in which systems are investigated.

C. THE PERSONNEL INVOLVED

The Computer Professionals

There are three key groups of specialist computer professionals involved in systemsdevelopment systems analysts, systems designers and programmers. However, the exactdemarcation lines between analysis, design and programming are not very precise and varyfrom organisation to organisation. In some companies the programmers will design detailedfile and report layouts, working from an overall specification provided by the systems

designers. As the use of programming aids becomes more widespread, and the workinvolved in detailed coding is therefore reduced, this division between different kinds ofcomputer professionals will become even more blurred. It is, though, a useful distinction todraw in order to consider the roles involved at different stages in the development process.

(a) The Systems Analyst

We can say that the general role of systems analysts is continually to update theinformation system of an organisation. They will maintain a continual survey ofinformation requirements and propose changes in (or design new) systems, control theimplementation of the designs and monitor their operation.

Systems analysts are responsible for the analysis, specification and implementation ofcomputing or computing-related projects assigned to them. It is thus essential that theanalyst has both computer and business knowledge and experience. The job has avery wide scope, and perhaps there is a need to divide it into two an investigator withbusiness training and a designer with a background in computers.

(b) The Systems Designer

System designing can be defined as the act of analysing and documenting existingsystems, and more particularly the act of creating new systems meeting definedobjectives.

Systems designers can work in one of two ways:

(a) converting an existing system (usually clerical) into another (usuallycomputerised) system; or

(b) creating an entirely new system to meet an entirely new need.


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It is obvious, therefore, that the specification of requirements stage is again veryimportant. If management is looking for a sophisticated, far-seeing system but doesnot specify this, then what it may find itself provided with is merely the existing systemmechanised or computerised.

Essentially, the activities of system designers centre around converting what is to be

done (given by the requirement specification) into how it is to be done. They will thushave to undertake the following tasks:

Study the requirement specification and determine the overall system in terms ofinput, output, processing and storage.

Design, in detail, the layouts of all output documents, reports and displays to beproduced by the system and define their expected frequencies and volumes,where these are not clearly expressed in the requirement specification.

Determine the processing logic of the system; this will define the programs whichare required, the functions they will carry out and the order in which they will run.

Very carefully determine all the control, validation and audit procedures needed in

the system, so that these can be incorporated into the design at the appropriateplaces.

Design the input data layouts and define expected volumes, frequencies, etc.

Specify and design the secondary memory files; this will include detailed recorddesign, file organisation decisions, estimated volumes, update frequencies,retention periods, security and control procedures.

Finalise the data specifications for input, output and storage to ensure nothinghas been overlooked.

Design the manual procedures associated with the new system.

Define the system test requirements which are to be used, to ensure that thesystem is operating correctly.

(c) The Programmer

Programmers take the very precise design specifications and turn them into computercode which can be understood by the computer.

It is very important that they work closely with the design and code it as written andspecified.

The programmer will run the tests of the code as set down by the designer. Anyproblems will be reported back to the designer for changes to be made to the design.

The programmer will also be involved in the actual implementation of the system in

order to provide any necessary last minute coding changes.

A major area of work for programmers is in systems maintenance. During theoperating life of all systems, various bugs will appear in the code. A programmer isresponsible for correcting these in consultation with the designer.

From time to time, enhancements will be proposed for the system and again theprogrammer will be closely involved in coding the design changes.


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Users as Clients

Gone are the days when computing staff were the sole technical experts and the people whorelied on their systems were known as "users", although you will have noticed that wecontinue to refer to "users" in this course. Information Technology staff now use systemsengineering techniques to develop products for the requirements of users as clients i.e. to

meet what they, the eventual users, require. Such products may even operate on the client'sown hardware or may form part of a total facilities management service provided by the ITdepartment or external contractor.

A feature of business today is "total quality" and this introduces concepts such as:

Get it right first time/zero defects.

Internal clients (other departments in the company).

Continual improvement.

It is now, therefore, more important than ever that the client participates fully in the design,development, implementation and operation of the product.

We have already reviewed the structure project teams for this process. For the purposes ofthis study unit, however, we shall consider the following categories of client:

senior management

junior management

client staff.

Depending upon the size of system and organisation, there will be more or less overlapbetween these categories. In a small business one person may perform all roles, whereas ina large organisation many people may be involved.

(a) Senior Management

The client should be represented at a senior level by one person who is the finaldecision maker on all matters relating to the project. He or she will make the "go/nogo" decision at the end of each stage of the development process, but is unlikely to beinvolved in the day-to-day activities of the project team.

Senior management's responsibilities can be summarised as:

agreeing terms of reference for the project

defining critical success factors

reviewing progress on a regular basis

"signing off" each major deliverable

agreeing budgets and schedules.

(b) Junior Management

These are the people who will have regular contact with, and may even be part of, theproject team. Working closely with the IT development staff they will need anappropriate degree of "IT literacy" and have a good understanding of themethodologies being used. That is not to say they should be IT experts since a goodmethodology will be readily understandable by most people.

They are likely to be managers/supervisors from the departments most affected by theintroduction of the new system and thus in a good position to define the detailedrequirements. During the operational phase of the system they will be key players in

ensuring its success.


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The responsibilities of junior management can be summarised as:

Defining detailed objectives.

Confirming "deliverables" meet client requirements.

Making recommendations to senior management.

Assisting in quality assurance.

Participating in client acceptance.

Helping to design training procedures.

Participating in training activities.

Assisting the implementation process.

Using the implemented system.

(c) Client Staff

These are the people who will be using the system on a day-to-day basis. Some may

be involved in the development process as part of the project team but their mainresponsibilities will be to:

Assist the development process.

Undertake trainin

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