System Development Process Prof. Sujata Rao

2Overview Systems 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

3 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 project Successful development project: – Provides a detailed plan to follow – Organized, methodical sequence of tasks and activities – Produces reliable, robust, and efficient system

4 Phases of the S D L C Project planning: initiate, ensure feasibility, plan schedule, obtain approval for project Analysis: understand business needs and processing requirements Design: define solution system based on requirements and analysis decisions Implementation: construction, testing, user training, and installation of new system Support: keep system running and improve

5 Information System Development Phases

6 The waterfall approach to the SDLC

7 Overlap of Systems Development Activities

8 Iterations across life cycle phases

S D L C Initiating a Development Request 1. P lanning 2. Feasibility Study 3. Specifying System /User Requirements 4. System Analysis & Design 5. System Implementation 6. Testing 7. Conversion 8. Operation & evalation 9. Documentation

S D L C 1. Planning 1. Corporate Goals 2. Available Resources 3. Organisational Constraints 4. Technological trends 5. Competitive Environment 2. Feasibility Study 1.Economic feasibility Estimate cost against proposed soln., DC, Ind. Cost, CBA 2.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 Requirements 1. Reports to be generated 2. Process to be performed 3. Inputs needed 4. 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

15 Required Skills of the Systems Analyst

16 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

17 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

18 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

19 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 packages Analyst understands SDLC phase techniques: – Project planning – Systems analysis, systems design – Construction, implementation, systems support

20 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

21 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

22 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)