anaysis systems

7/30/2019 Anaysis Systems

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Anaysis Systems

Determining Requirements


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The Objective is

To gather & record facts about the current

systemwhether it is manual or computer

basedWhat is required to support business needs.


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Determining

Requirement

Analyzing Requirement

Evaluating Alternatives

& Strategies

Analysis Systems


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Preliminary Investigation

Report

Determine the FactsObjective:

To get the facts

Analyze the FactsObjective:

To study the facts

Make a DecisionObjective:To prepare the systems requirements document

Next Phase or Terminate the poject

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Emphasizes the process of gathering facts

about the current system & proposed

changes


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Gather information on what system should

do from many sources

Users Reports

Forms

Procedures


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Types of deliverables:

Information collected from users

Existing documents and files Computer-based information

Understanding of organizational components

Business objective

Information needs

Rules of data processing

Key events


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Tips

To be successful during systems analysis, you

must have both skils:

Critical-Thinking Skill

Interpersonal Skill


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The 5 Magic Questions :

Who

What

When

Where

How

Why ?


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Examples:

Who?

Who performs each of the procedures within thesystems? Why? Are the correct people

performing the activity? Could other peopleperfom the tasks more eefectively?

What?

What is being done? What procedures are beingfollowed?Why is this process necessary?(often,procedures have been followed for many years &no knows why. You should question why a

procedure is being followed at all)


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Where?

Where are operations being performed?why?

Where could they be performed? Could they beperformed more efficiently elsewhere?

When?

When is a prosedure performed?why is it beingperformed at this time? Is this the best time?


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How?

How is a procedure performed?why is it

performed in this manner?could it be performedbetter, more efficiently, or less expensively in

some other manner?


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Requirement Determination

What is done? Why is it done?

Where is it done? Why is it done?

When is it done? Why is it done then

Who does it? Why does this person do it?

How is it done? Why is it done this way?

Requirement Analysis

What should be done?

Where should it be done?

When should it be done?

Who should do it?

How should it be done?


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Systems Requirement

Interviews

Other Fact-Finding Techniques

Recording The Facts

Other Systems Development Techniques


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Determining RequirementsSystems

Requirements

Outputs

Inputs

Processes

Timing

Controls

Volumes, Sizes & Frequencies


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Determining RequirementsI nterviews

Determine the People to Interview

Establish Objectives for Interview

Prepare for the Interview

Conduct the Interview

Document the Interview

Evaluate the Interview

Unsuccessful Interview


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Determining RequirementsOther Fact-Finding

Techniques

Document Review

Observation

Questionnaires

Sampling Work & Work People

Graphics

Research


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Determining RequirementsRecording The Fact

The Need for Recording the Facts

Software Tools


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Determining RequirementsOther Systems

development Techniques

Join Application Design (JAD)

Prototyping

Business Process Reengineering (BPR)

Rapid Application Development (RAD)

Object Oriented Systems Development


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JADJoin Application Design

Brings together key users, managers and systemsanalysts (who document and record the result &decisions)

Purpose: collect system requirementssimultaneously from key people

The Objective : analyze the existing system, workon potential solutions & agree on requirements for

the new system.The JAD team usually meets over of days orweeks, in a spesial conference room or at an off-site location.


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JADParticipants

Participants

Session Leader

Users Managers

Sponsor

Systems Analysts Scribe

IS Staff


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JADEnd Result

End Result

Documentation detailing existing system

Features of proposed system


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Prototyping

Repetitive process

Rudimentary version of system is built

Replaces or augments SDLC

Goal: to develop concrete specifications for

ultimate system


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Prototyping

Quickly converts requirements to working version ofsystem

Once the user sees requirements converted to system,

will ask for modifications or will generate additionalrequests

Most useful when:

User requests are not clear

Few users are involved in the system Designs are complex and require concrete form

History of communication problems between analysts andusers

Tools are readily available to build prototype


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Prototyping - Drawbacks

Drawbacks

Tendency to avoid formal documentation

Difficult to adapt to more general user audience Sharing data with other systems is often not

considered

Systems Development Life Cycle (SDLC)checks are often bypassed


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Business Process Reengineer ing (BPR)

Search for and implementation of radical change

in business processes to achieve breakthrough

improvements in products and servicesGoals

Reorganize complete flow of data in major sections

of an organization Eliminate unnecessary steps

Combine steps

Become more responsive to future change


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Identification of processes to reengineer

Key business processes

Set of activities designed to produce specific outputfor a particular customer or market

Focused on customers and outcome

Same techniques are used as were used for

requirements determination


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Identify specific activities that can be

improved through BPR

Disruptive technologies Technologies that enable the breaking of long-

held business rules that inhibit organizations

from making radical business changes


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Rapid Application Development (RAD)

RAD is a general strategy rather than a single

methodology

Goals To analyze a business process rapidly

To design a viable system solution through intensecooperation between users and developers

To get the finished application into the hands of the users

quicklyTraditional SDLC steps are followed, but phases arecombined

Iteration is limited to design and development phases


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RADComponents

User involvement is key to success

Prototyping is conducted in sessions similar

to Joint Application Design (JAD)Prototyping screens become screens within

the production system

CASE tools are used to design theprototypes


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RAD - CASE and Visual Development

Environments

Types of CASE tools

Diagramming tools

Computer display and report generators

Analysis tools used to check for incomplete, inconsistent orincorrect specifications

A central repository

Documentation generators

Code generatorsForm and report generators

CASE tools that support the creation of system forms andreports in order to prototype how systems will look and feel

to users


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Code Generators

CASE tools that enable the automatic

generation of program and database definitioncode directly from the design documents,

diagrams, forms and reports stored in the

repository


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Approaches to RAD

James Martins pillars of RAD

Tools

People Methodology

Management


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Approaches to RAD

Software Tools

Case tools can be used for

Prototyping Code generation


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Martins RAD Life Cycle

Systems requirement determination is done in context of a

discussion of business problems and business areas

User Design

End users and IS professionals participate in JAD workshops

CASE tools are used to support prototyping

Construction

Designer creates code using code generator

End user validates screens and other aspects of design

Cutover

New system is delivered to end users


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SUMMARY

Interviews

Open-ended and close-ended questions

Preparation is keyQuestionnaires

Must be carefully designed

Can contain close-ended as well as open-endedquestions


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Other means of gathering requirements

Observing workers

Analyzing business documentsJoint Application Design (JAD)

Prototyping

Business Process Reengineering (BPR) Disruptive technologies

RAD

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