btec national diploma in computing systems analysis and design 02/07/2015by: douglas eke1 systems...

BTEC National Diploma in ComputingSystems Analysis and Design

19/04/23 By: Douglas Eke 1

Systems Analysis and Design

An Introduction

to

Fact Finding Techniques



SSADM – Knowledge Test

Complete the tasks below:

1. Why is a structured approach necessary?

2. What are the main advantages and disadvantages of the waterfall model?

3. What are the main advantages and disadvantages of rapid applications development?

4. Why might people be optimistic about the cost of projects?

5. Identify the problems that could develop if the system scope is not sufficiently clarified at the start of a project?



Objectives

At the end of this lecture you should be able to:

- Appreciate the need for accurate and complete information.

- Define the tools and methods used by the Systems Analyst.

- Explain the benefits and drawbacks of each information gathering technique.



Computerised Information Systems Suppose the Systems Analyst has a project:

To design a computerised information system and network.

The Analyst wants to find out:

- What the users want from the system.

- What information the system needs to handle and what documentation needs to be produced.

- What the Organisational Management are hoping to achieve from the system.



What do we need to find out?

At first, we know nothing about what the users want…

….and maybe a little about the organisation (which may be any business area).

We need to find out about: Their circumstances including constraints Their problems What they want



What do we need to achieve? The goal is simple: to learn enough to develop an IS that will

be useful to:

These specific users These particular circumstances These unique problems

We must also document what we learn, so others can access our knowledge.



User requirements What is useful depends on the type of information that matters

to the users

We may need to capture details of:

Timing and sequence. Data (structure and data relationships). Processes. Other aspects e.g. user issues, legislative and safety

factors.



Fact Finding The Systems Analyst needs to find out about the project

requirements using a variety of different information gathering techniques.

This is known as fact finding



S.Q.I.R.O.To remember each of the fact finding techniques, remember S.Q.I.R.O.

S is for Sampling (existing documents)

Q is for Questionnaires

I is for Interviewing

R is for Research (background reading)

O is for Observation.



S is for…Sampling Having too much information can

be overwhelming…imagine trying to read a telephone directory!

Sometimes we just need to see some of the information – a sample.



Sampling A sample gives an overview of the information that is being

processed but we must make sure that the sample:

has been obtained in a sensible manner

and

is an unbiased representation of the complete set of information available.



Sampling

Sampling is almost always used. Why?

Can be used to support other techniques.

Adds further details to information already gathered.

Can resolve errors and ambiguities.

Identifies precise data content and structures.

Confirms sequence of input/output.

Identifies flow of work from one user to another.



Q is for…Questionnaires A questionnaire is a way of enabling a large number of people

to express their views.

Questionnaires are useful:

- when there is a large user base

- when there are geographically dispersed users

- as a starting point, for following up with interview, etc.



Questionnaires

Caution! Questionnaires are difficult andtime consuming to design, use and analyse.

How many questions? Open or closed questions?

As there is no interaction with the respondent: How do we avoid ambiguous questions? How do we pilot the questionnaire to make sure the responders correctly interpret the questions?

How can we obtain a sensible response rate?

How do we analyse the responses? What if some responders have missed out questions or given silly answers?


19/04/23 By: Douglas Eke 1519/04/23 By: Douglas Eke 15

Questionnaires

Task You work for a games development company and have been requested to develop a questionnaire that can be sent out to the gaming community to determine the type of games played (genre), length of time and periods they play the games.

It is also important to establish their geographic location as well as details about age, gender.

It would also be good to get an indication as to the preference of genre for the development of a new computer game.



I is for…Interviewing

Most widely used technique.

Often done

top-down through the organisation.



Interviewing Useful for in-depth questioning of particular employees.

Flexible (can be tailored to the individual and interviewer can probe where necessary).

Interviewer requires sensitivity and good communications skills.

Can be time consuming.



Interviewing

Two main approaches to interviewing

Formal – Must be planned, following a set agenda and time limit

Informal – You have a general agenda, but can deviate depending on the answers and can run over time if necessary

Both should be booked though.



R is for…Research

Research/background reading of written documentation in the Organisation is particularly useful at the start of a project to find out:

How the organisation conducts their business

The Organisation’s objectives, Strategic plan, financial performance, legal situation, etc.

Possible areas of development…



ResearchWhat particular documents would be useful for the Systems Analyst to read?

Official company reports – to give an overview of the company and system.

Company organisation chart - to identify users of the system (for interview planning)

External sources, e.g. journals - can give ideas for solution to problems.



O is for…Observation

Observation: Shows the problems that the

staff are experiencing.

Resolves conflicting stories. (Can see what really happens not what people think happens!



ObservationObservation: Confirms the detail of

complex processes.

Could suggest to the analyst a possible solution.



Observation

Note

As the focus of observation is on the ergonomics and workflow, some employees/organisations feel uncomfortable being so closely observed, so

consequently this fact finding technique is less readily used.

Note

As the focus of observation is on the ergonomics and workflow, some employees/organisations feel uncomfortable being so closely observed, so

consequently this fact finding technique is less readily used.



Establishing user Requirements At the start we know nothing at all

By the end we have

Decided more or less what matters

Found out what the users want

Recorded this in a useful way



Summary

You should now know:

The need to gather information before we can analyse and design a system.

The names of the 5 different fact-finding techniques in the pneumonic S.Q.I.R.O.

The benefits and limitations of each of the fact-finding techniques.

The Systems Analyst needs to have a range of interpersonal skills; you will be expected to demonstrate these same skills in tutorials.



References

Eva and Skidmore (2004). Introducing Systems Development. Palgrave Macmillan.

Satzinger JW, Jackson RB and Burd SD (2004). Systems Analysis and Design in a Changing World. 3rd edition. Thomson.

Slides originally from De Montfort University INFO1409 Systems Analysis SQIRO L07.ppt

btec national diploma in computing systems analysis and design 02/07/2015by: douglas eke1 systems...

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