copy of case tool@vx - · pdf file9/1/2011 · automating some activity of system...

CASE ToolsCASE ToolsCASE ToolsCASE Tools

by:-Assit. Prof. Vijay Vora

(SOOADM) MCA-III(Murlidhar Group of Institutions , Rajkot) 1

•• What is CASE tool ?What is CASE tool ?

– CASECASE refers to the CComputer AAided SSoftware

EEngineering Tools or

– CComputer AAided SSystem EEngineering Tools.

– What is the Tool?

• Tools are any devices or aid that improve the • Tools are any devices or aid that improve the

performance of a task , when it used properly.

– CASE tools are the powerful soft wares used for

automating some activity of system

development.



– In the field of System Engineering, Computer

Aided Software Engineering (CASE) tools are the

set of scientific application tools and these tools

helps in development of high-quality, defect-free,

and maintainable systems or software.

– CASE tools automate methods for designing,

documenting, and producing computer code in documenting, and producing computer code in

the desired programming language.

– Key Ideas of CComputer AAided SSystem EEngineering Tools.

I. Providing of computer assistance in system

development and system maintenance processes.

II. An engineering approach for development and

maintenance of the software .by:-Assit. Prof. Vijay Vora


•• Advantages of using CASE toolsAdvantages of using CASE tools

– Improve overall system quality.

– Decrease design time.

– Decrease required effort and time in application testing.

– Improve effectiveness of system management activities

– Improve productivity (output).

– Development activities can be completed in less time.– Development activities can be completed in less time.

– Decrease required efforts and time in application

maintenance activities.

– Automats tedious tasks. Some tasks in system

development, like the development of data flow

diagrams can be very time consuming, this can be done

automatically using case tools.by:-Assit. Prof. Vijay Vora


•• Prerequisites of using CASE toolsPrerequisites of using CASE tools

– Need a collection of useful tools that help in every step

of building a system.

– Need a plan that enables tools to be found quickly and

use efficiently.

– Need a skilled person who understands how to use the

tools effectively.

•• Use of CASE toolsUse of CASE tools

– Used in requirement analysis and design support

– Used in code generation

– Used in report generation

– Used in documentation

– Used in test case generationby:-Assit. Prof. Vijay Vora


•• Categories of CASE ToolsCategories of CASE Tools

– CASE tools can be categorized in three categories.

I. Front-End tools (High-Level tools, Upper-CASE tools)

II. Back-End tools (Lower CASE tools)

III. Integrated tools

I. Front-End tools I. Front-End tools

– In the terms of Software Engineering, Upper-CASE tools

are the tools that automate or support the “upper” or

earliest phases of systems development.

– It helps to automate the activities like requirements

analysis, planning and preparing the logical design of

system.by:-Assit. Prof. Vijay Vora


– Some of the front-end tools are used for analyzing the

requirements those are gathered in requirement phase.

– It helps in designing the system.

– It helps to draw Data Flow Diagrams, Process diagrams,

E-R diagrams, Structured charts, flow charts etc.

– front-end tools are also called diagramming tools.

– If changes are to be made, analyst just has to mention

the required changes and then it redraw entire diagram the required changes and then it redraw entire diagram

automatically.

– This type of tool helps to eliminate the tedious and

laborious activities of changing and redrawing the

design.



II. BackII. Back--End tools End tools (Lower CASE tools)(Lower CASE tools)– Back-end CASE tools or lower case tools describes tools

that automate or support the “lower” or later phases of systems development.

– For Eg. Development(coding), Implementation, testing, maintenance.

– They are used in software development.

– It helps to create actual program code on the basis of – It helps to create actual program code on the basis of previous(upper CASE) activities.

– Actually it can construction the code using any one programming language or more than one programming languages.

– This type of tool is general purpose tool.

– They are not limited to any specific application so fully automatic code generation is not possible.



– Almost 70% to 75% code can be generated.

– Rest of the coding can be done by hard coding.

– Some back-end tools are used for input designing and

output designing.

– They are also called Interface generator because they

help to generate user interaction screens.

– A ‘Report generator tool’ or a ‘Report Writer tool’ can be

used for creating formatted reports.used for creating formatted reports.

– Some back-end tools can be used for system

implementation purpose and training and testing

purpose.



III. Integrated toolsIII. Integrated tools ((IIIIIIII--CASE tools)CASE tools)

– Front-end tools focus on high-level activities and Back-

end tools can focus on low-level activities.

– Integrated CASE tools are combination of both front-end

tools and back-end tools.

– They support the entire SDLC to develop a system.



InterviewingInterviewing



•• What is Interviewing? What is Interviewing?

– Interviewing is one type of Fact-Finding

Techniques.

– The methods which are used by analysts for

collecting data about requirements are called

fact-finding techniques

– Interviewing is used to collect information from – Interviewing is used to collect information from individual or from groups.

– Interviewee (respondents) are generally

current users of the existing system or

potential user of the proposed system.



– This method is the best source of qualitative

information.

– Interviews reveal(tell) information about:

• Interviewee opinions.

• Interviewee feelings.

• About the current state of the system.

• Organizational and personal goals.• Organizational and personal goals.

• Informal procedures.



• Planning the Interview

–Five steps for planning the interview :

1. Reading background material.

2. Establishing interview objectives.

3. Deciding whom to interview.

4. Preparing the interviewee.

5. Deciding question types and structure.5. Deciding question types and structure.



–There are some points which are considered as formalities which must be performed every time arranging and conducting interviews.

• Objectives and methods for interview must be clear

without conducting interviews.

• At the time of interview create friendly environment • At the time of interview create friendly environment

so that interviewee can share his ideas.

• Explain the subject of interview well in advance.

• It is always preferable not to argue with many people

during the interview.

• Interviews must cover narrow domain area including

very few informative topics.by:-Assit. Prof. Vijay Vora


– This method is the best source of qualitative information but it is time consuming process.

– There is also one big advantage is that, Interviewing allows the analysts to discover areas of misunderstanding.

– Interviewing can be either structured or unstructured.

–– Structured InterviewStructured Interview–– Structured InterviewStructured Interview

• In structured Interview the structure and the format of the question is predefine.

–– Unstructured InterviewUnstructured Interview

• In Unstructured Interview the format of the question is not predefine and there is flexibility in asking question.



Structured InterviewStructured Interview Unstructured Unstructured

InterviewInterview

AdvantagesAdvantages 1.1. Ensure uniform wording Ensure uniform wording

of the question for of the question for all all

respondents. respondents.

2.2. Easy to evaluate.Easy to evaluate.

3.3. Result in shorter Result in shorter

interviews.interviews.

1.1. Interviewer hasInterviewer has

greater flexibility in greater flexibility in

wording question to wording question to

suit respondentsuit respondent

DisadvantagesDisadvantages 1.1. Cost ofCost of preparation is preparation is 1.1. May be inefficient use May be inefficient use DisadvantagesDisadvantages 1.1. Cost ofCost of preparation is preparation is

high.high.

2.2. High level of structure High level of structure

may not be suitable for may not be suitable for

all situations.all situations.

1.1. May be inefficient use May be inefficient use

of both respondent of both respondent

and interviewer time.and interviewer time.

2.2. AnalysisAnalysis may be may be

lengthylengthy

3.3. Takes extra time to Takes extra time to

collect essential facts.collect essential facts.



• Closing the Interview

–Always ask “Is there anything else that like to add?”

–Summarize and provide feedback

–Ask whom to talk with next

–Set up any future appointments–Set up any future appointments

–Thank them for their time and shake hands



• Interview Report

–Write as soon as possible after the interview

–Provide an initial summary, instead of more detail

–Review the report with the respondent



QuestionnairesQuestionnaires



•• What is Questionnaires? What is Questionnaires? – Questionnaires is another type of Fact-Finding

Techniques.

– Questionnaires allows analysts to collect information about various aspect of a system from large number of persons.

– Questionnaires may be used as a supplementary – Questionnaires may be used as a supplementary to the interviews

– The use of standardized question formats can yield more reliable data or information.

– A questionnaire is considered as a structured interview form.



– Basically Questionnaires are useful in gathering

information from users/members about:

• Attitudes.

• Beliefs.

• Behaviors.

• Characteristics.

•• When to Use Questionnaires?When to Use Questionnaires?•• When to Use Questionnaires?When to Use Questionnaires?

– Organization members are widely dispersed.

– Many members are involved with the project.

– Examining work is needed.

– Problem solving prior to interviews is necessary.



•• Types of Questionnaires form? Types of Questionnaires form?

(Question Type)(Question Type)

1.1. OpenOpen--ended (Openended (Open--response)response)

2.2. ClosedClosed--response response



11.. OpenOpen--ended (Openended (Open--response)response)

– Open-ended questions are used for gathering

descriptive feedbacks from the group of people.

– Respondents must answer the question in their

own words.

– Space is provided under each question for the

response. response.

– In the case of Interview Open-ended questions

are used to learn about feelings, opinions, and

general experiences of interviewees.

– Open-ended questions are appropriate when the

analyst is interested in extent and depth of reply.by:-Assit. Prof. Vijay Vora


–– Advantages of OpenAdvantages of Open--Ended Questions Ended Questions

(in interviewing )(in interviewing )

• Ease give answer for the interviewees.

• Allows the interviewer for conversation in the

interviewee's language.

• Provides richness of detail.

• the interviewer can ask counter question on the base • the interviewer can ask counter question on the base

of previous discussion

• Provides more interest for the interviewee.

• Allows more naturalness

• Free to response in any word.

• Useful if the interviewer is unprepared.



–– Disadvantages of OpenDisadvantages of Open--Ended Questions Ended Questions


• May result in too much irrelevant detail.

• Possibility to losing objectives of the interview.

• May take too much time for to get small amount of

useful information.

• Potentially outward that the interviewer is • Potentially outward that the interviewer is

unprepared.

• Possibly to create bad impression that the interviewer

is on a "fishing expedition”



22.. ClosedClosed--responseresponse

– Close ended questions are used for short answers

– This answers may including even ‘Yes’ or ‘No’ i.e. Bipolar questions.

– Generally Close ended questions are use to obtain like or dislike of respondent.

– Response for close ended question is generally fixed and predictable.and predictable.

– In the case of Interviewing Closed interview questions limit the number of possible responses.

– Closed interview questions are appropriate for generating precise(exact) and reliable data that is easy to analyze.

– The methodology requires little skill for interviewers.by:-Assit. Prof. Vijay Vora


–– Advantages of Closed Questions Advantages of Closed Questions


• Saving interview time.

• Easily evaluate interviews.

• Getting information is to the point.

• Keeping control of the interview.

• Covering a large area quickly.• Covering a large area quickly.

• Getting to relevant data.

• Maximum meet the interviewing objective



–– Disadvantages of Closed Questions Disadvantages of Closed Questions


• Boring for the interviewee.

• Failure to obtain rich detailing.

• Missing main ideas.

• Failing to build relationship between interviewer and

interviewee.interviewee.



•• Attributes of OpenAttributes of Open--ended and Closed Questionsended and Closed Questions



��Bipolar Questions and ProbesBipolar Questions and Probes(sub category of open/close question)(sub category of open/close question)

–– Bipolar QuestionsBipolar Questions

• Bipolar questions are those that may be answered

with a ‘yes’ or ‘no’ or ‘agree’ or ‘disagree’

• Bipolar questions should be used sparingly( ,

carefully)

• A special kind of closed question

• This type of closed question limits the interviewee by

allowing a choice on either “pole”, such as yes or no,

true or false, agree or disagree.



–– Probes QuestionsProbes Questions

• Probing questions find out more detail about previous questions

• The purpose of probing questions is:

–To get more meaning

–To get clarification

–To draw out and expand on the interviewee's point

• Some of the strongest probe questions are put • Some of the strongest probe questions are put restriction on accepting superficial answers.

• These type of questions are used to obtain more detail when a previous question has not give up satisfaction or sufficient information.

• For example,

– ‘why?’,

– ‘please could you tell me more about . . . ?’by:-Assit. Prof. Vijay Vora


•• Question Sequencing/Arranging Question Sequencing/Arranging

Questions Questions

– There are some systematic structures are use to

arranging questions in Questionnaires as well as

in Interviewing.

– There three basic way to arranging questions

1.1. PyramidPyramid

2.2. FunnelFunnel

3.3. DiamondDiamond



11.. Pyramid (Inductive Approach)Pyramid (Inductive Approach)

– Starting with closed questions and working

toward open-ended questions

– In this approach questioning start with very

detailed closed questions

– And than after it expands by allowing open-

ended questions and it will be more generalized ended questions and it will be more generalized

on the bases of responses of respondent

– Is useful if interviewees need to be warm up to

the topic or seems uncomfortable to address the

topic.



– The figure shows the Pyramid structure for

interviewing goes from specific to general

questions



22. Funnel (Deductive Approach). Funnel (Deductive Approach)

– Starting with open-ended questions and working

toward closed questions

– In other words it begins with generalized, open-ended questions and concludes by narrowing the possible responses using closed questions

– the interview begins with open questions at the – the interview begins with open questions at the wide end of the funnel, followed by closed ended probing questions to focus on specific points.



figure shows the

Funnel structure



33. Diamond. Diamond

– starting with closed, moving toward open-ended,

and ending with closed questions

– Diamond is combination of both Pyramid Pyramid andFunnelFunnel

– A diamond-shaped structure begins in a very

specific wayspecific way

– Then more general issues are examined

– Concludes with specific questions

– It Takes longer time and effort than the other

structures



– The figure shows the Diamond structure



•• Questionnaire LanguageQuestionnaire Language– Simple.

– Specific.

• Use the specific wording rather than the vague(વેગ - unclear)

in wording

– Free of bias(બાયસ / partiality).

– Not patronizing(પેનાઇઝ�ગ / demeaning).– Not patronizing(પેનાઇઝ�ગ / demeaning).

– Technically (theoretically/ exactly ) accurate.

– Addressed to those who are knowledgeable.

• target questions to correct respondents.

– Appropriate for the reading level of the respondent.



•• Questionnaire Measurement ScalesQuestionnaire Measurement Scales– Scaling is the process of assigning numbers or other

symbols to an attribute or characteristic for the purpose

of measuring that attribute or characteristic.

– Using Measurement scale respondents act as judges for

the subject of the questionnaire

– The four different forms of measurement scales are:– The four different forms of measurement scales are:

•• NominalNominal

•• OrdinalOrdinal

•• IntervalInterval

•• RatioRatioby:-Assit. Prof. Vijay Vora


•• Nominal ScalesNominal Scales– Nominal scales are used to classify things

– It is the weakest form of measurement

– Data may be limited



•• Ordinal ScalesOrdinal Scales– It allows classification

– Ordinal scales also imply rank ordering

– There is no difference between the importance of

the choices

The support staff of the Technical Support Group is:The support staff of the Technical Support Group is:



11. Extremely Helpful. Extremely Helpful

22. Very Helpful. Very Helpful

33. . fairly fairly HelpfulHelpful

44. Not Very Helpful. Not Very Helpful

55. Not Helpful At All. Not Helpful At All

•• Interval ScalesInterval Scales– An interval scale is used when the intervals are

equal

– There is no absolute zero

– Examples of interval scales include the Fahrenheit

or Centigrade scale



How useful is the support given by the Technical Support Group?How useful is the support given by the Technical Support Group?NOT USEFULNOT USEFUL EXTREMELYEXTREMELY

AT ALLAT ALL USEFULUSEFUL1 2 3 4 51 2 3 4 5

•• Ratio ScalesRatio Scales– When the intervals between numbers are equal

at that time Ratio Scales are use

– Ratio scales have an absolute zero

Approximately how many hours do you spend on the Internet daily?Approximately how many hours do you spend on the Internet daily?



0 2 4 6 80 2 4 6 8

•• Guidelines for Using ScalesGuidelines for Using Scales

– Use a ratio scale when intervals are equal and

there is an absolute zero

– Use an interval scale when intervals are equal but

there is no absolute zero

– Use an ordinal scale the intervals are not equal

but classes can be rankedbut classes can be ranked

– Use a nominal scale when classifying but not

ranking



•• Problems With ScalesProblems With Scales

– Construction of scales is a serious task which

must consider the problems associated with their

construction.

– There are three problems associated with poorly

constructed scales:

•• Leniency (Leniency (લીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સ / kindness)/ kindness)•• Leniency (Leniency (લીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સ / kindness)/ kindness)

•• Central tendency (Central tendency (વલણવલણવલણવલણવલણવલણવલણવલણ))

•• Halo effectHalo effect



•• Leniency (Leniency (લીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સલીિનઅ��સ / kindness)/ kindness)

– Caused by easy raters

– A solution is to move the “average” category to

the left or right of center

•• Central TendencyCentral Tendency

– Central tendency occurs when respondents rate – Central tendency occurs when respondents rate

everything as average

– Problem by miss measurement of smaller and

larger value.

– Adjusting the strength of the descriptors

– Creating a scale with more pointsby:-Assit. Prof. Vijay Vora


•• Halo EffectHalo Effect

– When the impression formed in one question

carries into the next question

– Solution is to place one characteristic and several

items on each page



•• Validity And Reliability of QuestionnaireValidity And Reliability of Questionnaire

–Questionnaires must be valid and reliable.

–Reliability of scales refers to consistency in

response. Getting the same results if the

same questionnaire was administered again

under the same conditionsunder the same conditions

–Validity is the degree to which the question

measures and what the analyst intends to

measure



•• Formatting / Designing the QuestionnaireFormatting / Designing the Questionnaire

–Good response rates can be achieved with consistent control of questionnaire

–Following points are keep in mind at the time of designing the Questionnaire

•• FormatFormat

•• StyleStyle•• StyleStyle

•• Meaningful orderingMeaningful ordering

•• Clustering of questionsClustering of questions

–Questionnaire must be a well designed because relevant questionnaire can help to overcome some of the resistance



•• Questionnaire FormatQuestionnaire Format

–When designing questionnaires

• Allow ample (enough) white space

• Allow enough space for responses to be typed

for open-ended questions

• Ask respondents to clearly mark their answers• Ask respondents to clearly mark their answers

• Use objectives to help determine format

• Be consistent in style



•• Order of QuestionnaireOrder of Questionnaire

–Most important questions go first

–Similar topics should be clustered together

–Randomization of questions tries the

patience of respondents

–Controversial questions should be –Controversial questions should be

positioned after less controversial questions



•• Designing Web Form QuestionnaireDesigning Web Form Questionnaire

–Controls (fields) used on Web forms for

designing purpose

• Single line text box

• Scrolling text box, used for one or more

paragraphs of textparagraphs of text

• Check box for yes-no or true-false answers

• Radio button for mutually exclusive yes-no or

true-false answers

• Drop-down menu for selection from a list

• Submit or Clear buttonsby:-Assit. Prof. Vijay Vora


•• Administering the QuestionnaireAdministering the Questionnaire

–Methods of administering the questionnaire

include

• Convening All concerned respondents together

at one time

• Personally administering the questionnaire• Personally administering the questionnaire

• Allowing respondents to self-administer the

questionnaire

• Mailing questionnaires

• Administering over the Web or via email



JADJADJADJAD



•• What is JAD?What is JAD?– JAD is an abbreviation of Joint Application Joint Application

DesignDesign

– Now a day JAD is also refer to as a Joint Application Development

– JAD is a process used in the SDLC to collect business requirements while developing new system for a company. system for a company.

– Joint Application Development (JAD) is a development technique used to help IT developers to build the systems.

– Originally, JAD was designed to bring system developers and users of varying backgrounds and opinions together in a productive and creative environment. by:-Assit. Prof. Vijay Vora


•• Origin of JAD?Origin of JAD?

–Joint Application Design (JAD) was

developed by IBM developers Chuck Morris

and Tony Crawford in the 1970's.

–In 1980 Crawford and Morris taught JAD in

Toronto and Crawford led several Toronto and Crawford led several

workshops to prove the concept.

–The results were encouraging and JAD

became a well accepted approach in many

companies.



•• More about JAD?More about JAD?

– In this technique, a team is formed of members of different backgrounds.

– These members are made up of end-users, management, and IT staff.

– This team meets and discusses the current project in a number of workshops/sessions.project in a number of workshops/sessions.

– These workshops are used to define the project and to design a solution.

– Since the team includes actual users of the current system and the system analyst will have a better picture of what the clients would want in a new system.



•• When working in a JAD?(When to Use JAD)When working in a JAD?(When to Use JAD)

– Users are restless and want something new.

– It Use when the organizational culture supports joint problem-solving behaviors

– It use when the best people that understand their job functions and these are the people that perform those duties.that perform those duties.

– So one can say that, these people are the best source of information when a question comes up about a particular process.

– JAD is worth-full to build the bridge between the IT people and non-IT people (i.e. business professional).



– In the case of IT people, they can easily

gives the answer or can understand, what

happen behind the scenes in current

working system.

–But in the case of business professional,

they can easily gives the answer of

subjective matters.

–So to bridge that communication gap JAD

technique is use



•• Participants of JADParticipants of JAD

(Who Is Involved? / JAD Personnel / (Who Is Involved? / JAD Personnel /

Basic Components of a JAD session )Basic Components of a JAD session )

��SponsorSponsor

��AnalystAnalyst

��business usersbusiness users

��IT professionalIT professional

��Session leaderSession leader

��ObserversObservers

��record keeper(Scribe)record keeper(Scribe)by:-Assit. Prof. Vijay Vora


��SponsorSponsor• This is the executive of the organization chartering

the project.

��AnalystAnalyst• Analyze the collected information

��business usersbusiness users• These users can be of two type, first is upper

management and second is the actual end-users management and second is the actual end-users of the system.

• The upper management members are the members that will give insight(deep Information) on how the system will achieve the goals of the organization while the end-users will give detailed information on the day-to-day operations of the system.



��IT professionalIT professional

• These members can be the inside IT staff.

��Session leaderSession leader

• These are the users that has excellent

communication skills to describe the session

��ObserversObservers��ObserversObservers

• Technical experts from the functional areas for

the perfect advice.

��record keeper(Scribe)record keeper(Scribe)

• This person documents everything that

happens in these JAD sessionsby:-Assit. Prof. Vijay Vora


•• JAD Life CycleJAD Life Cycle

[Draw figure in explanation][Draw figure in explanation]

–Planning/Definition

–Preparation

–Design Sessions

–Finalization



•• Suggestions to Make Successful JADSuggestions to Make Successful JAD

(Guidelines for a Successful JAD)(Guidelines for a Successful JAD)– Make sure the analyst is fully trained

– Conduct an orientation(direction) for all participants

– Make sure user representatives are properly trained

– Do not begin another JAD session/role until one – Do not begin another JAD session/role until one JAD session/role is fulfill.

– Hold sessions off site

– Start the sessions only when all decision makers are present

– Document all assumptions and issues

– Assign responsibility and resolve all issuesby:-Assit. Prof. Vijay Vora


•• Benefits of JADBenefits of JAD

–Accelerates design

–Enhances quality

–Creates a design from the customer's

perspective

–Lowers development and maintenance

costs

–Time is saved

–Rapid development of systemsby:-Assit. Prof. Vijay Vora


•• Drawbacks of Using JADDrawbacks of Using JAD

–JAD requires a large block of time to be

available for all session participants

–If preparation is incomplete, the

session may not go very well.

–If the follow-up report is incomplete,

the session may not be successful.



•• ConclusionConclusion

–JAD is used as a technique for developing business system requirements and is typically used in the early stages of a systems development project.

–The purpose of JAD is to bring together upper users and end users in a structured workshop session to extract agreement based system requirements.



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