System Development Process Prof. Sujata Rao. 2Overview Systems development life cycle (SDLC) –...

System Development Process

Prof. Sujata Rao

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OverviewSystems development life cycle (SDLC)

– Provides overall framework for managing system development process

Two main approaches to SDLC– Traditional approach: structured systems

development and information engineering– Object-oriented approach: object technologies

requires different approach to analysis, design, and programming

All projects use some variation of SDLC

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Systems Development Life Cycle (SDLC)

Systems development project– Planned undertaking with fixed beginning and end– Produces desired result or product – Can be a large job of thousands of hours of effort

or a small one month projectSuccessful development project:

– Provides a detailed plan to follow– Organized, methodical sequence of tasks and

activities– Produces reliable, robust, and efficient system

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Phases of the S D L C Project planning: initiate, ensure feasibility, plan

schedule, obtain approval for projectAnalysis: understand business needs and

processing requirementsDesign: define solution system based on

requirements and analysis decisionsImplementation: construction, testing, user

training, and installation of new systemSupport: keep system running and improve

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Information System Development Phases

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The waterfall approach to the SDLC

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Overlap of Systems Development Activities

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Iterations across life cycle phases

S D L C Initiating a Development Request1. Planning2. Feasibility Study3. Specifying System /User Requirements4. System Analysis & Design5. System Implementation6. Testing 7. Conversion8. Operation & evalation9. Documentation

S D L C 1. Planning

1. Corporate Goals2. Available Resources3. Organisational Constraints4. Technological trends5. Competitive Environment

2. Feasibility Study1. Economic feasibility

• Estimate cost against proposed soln., DC, Ind. Cost, CBA2. Financial Feasibility

• To attain capital required for the project, to determine Fin. feasibility

3. Organisational Feasibility• Resource & Available Support System, Reaction to change

4. Technical Feasibility

S D L C 5. operational feasibility

If proposed soln can fit in existing operation , Tech & Eco. Feasibility may be possible but not procedural since difficult functionally

6. Other Feasibility Consideration Consider Internal & External constraints

3. Specifying System /User Requirements1. Reports to be generated2. Process to be performed3. Inputs needed4. Resources Required

SDLC contd…

4. System Analysis & Design– Output Design– Input Design– File Design– Process Design

5. System Implementation – Database Organisation– Preperation Of Documents & manuals– System orientation & Training

S D L C contd… 6. Testing

– Unit testing– Integration Testing – System Testing– Volume Testing– Acceptance Testing

7. Conversion– Parallel– Direct– Modular or Prototype Conversion– Phased Conversion

S D L C

8. Operation & Evaluation– Management : getting the activity completed.– Efficiency: the relationship with input &

output to minimise resource cost– Effectiveness: mission path to achieve the

goal

9. Documentation

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Required Skills of the Systems Analyst

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The Analyst as a Business Problem Solver

Has computer technology knowledge and programming expertise

Understands business problems

Uses logical methods for solving problems

Has fundamental curiosity

Wants to make things better

Is more of a business problem solver than technical programmer

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Analyst’s Approach to Problem Solving

Verify that the benefits of solving the problem outweigh the costs

Research and understand the problem

Define the requirements for solving the problem

Develop a set of possible solutions (alternatives)

Define the details of the chosen solution

Monitor to make sure that you obtain the desired results

Decide which solution is best, and make a recommendation

Implement the solution

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Required Skills of the Systems Analyst

An analyst should have fundamental technology knowledge of:– Computers / peripheral devices (hardware)– Communication networks and connectivity– Database and database management systems

(DBMS)– Programming languages (for example: VB.NET

or Java)– Operating systems and utilities

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Technical Knowledge and Skills

Analyst uses tools: – Software productivity packages (MS Office)– Integrated development environments (IDEs) for

programming languages– CASE tools / coding, testing, and documentation

support packagesAnalyst understands SDLC phase techniques:

– Project planning– Systems analysis, systems design– Construction, implementation, systems support

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People Knowledge and Skills

Interpersonal and communication skills are crucial to:– Obtaining information– Motivating people– Getting cooperation

– Understanding the complexity and workings of an organization in order to provide necessary support

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Integrity and Ethics Analyst has access to confidential

information such as salary, an organization’s planned projects, security systems, etc.

– Must keep information private

– Any impropriety can ruin an analyst’s career

– Analyst plans security in systems to protect confidential information

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The Environment Surrounding the Analyst

Types of Technology Encountered

– Desktop

– Networked desktops

– Client-server

– Mainframe

– Internet, intranet, and extranet

– Wireless, PDAs, Cell Phones (mobile workers)