Software Development Life Cycle (SDLC).pptx
- 3. Systems Development Participants Steering committee- The firms that take system strategy seriously establish a steering committee ◦ Chief Executive Officer ◦ Chief Financial Officer ◦ Senior Management from computer Services & user areas ◦ External Auditors ◦ Management Consultant Systems Professionals – analyze problems in current systems and formulate solutions ◦ systems analysts ◦ systems designers ◦ Programmers Client – the person or organization contracting to have the work done User – the people who will have contact with the system Stakeholders: individuals who have an interest in the system but are not end users
- 4. INTRODUCTION Accountants must understand the entire systems development process, since they are involved in several ways: ◦ Helping to specify their needs. ◦ As members of the development team. ◦ As auditors after the fact. Accountants also help keep the project on track by: ◦ Evaluating and measuring benefits. ◦ Measuring costs. ◦ Ensuring the project stays on schedule.
- 5. INTRODUCTION Effective systems analysis and design can ensure that developers: ◦ Correctly define the business problem. ◦ Design the appropriate solution.
- 6. System Development Life cycle SDLC is the process of developing information systems through investigation, analysis, design, implementation and maintenance. SDLC is also known as information systems development or application development. SDLC is a systems approach to problem solving and is made up of several phases, each comprised of
- 9. 1.Problem Definition Analyst prepares a written statement of the objectives and scope of the problem Conducts interviews with user Writes brief description of understanding of the problem and reviews it with both groups i.e. users/information analyst meeting.
- 10. 1.Problem Definition - Reason for the failure of existing system? - Programming errors in existing system? - Problems in or opportunities for improving the existing system? - Objectives of system investigation - Overview of proposed system - Expected costs & benefits of proposed system
- 12. 2.Feasibility Analysis Check whether the system is feasible or not A feasibility study is a test of a system proposal according to its workability, impact on the organization, ability to meet user needs and effective use of resources. Technical feasibility - is the technology necessary available? Economic feasibility - are the funds available and appropriate for the system? Legal feasibility - does the system fall within legal boundaries? Operational feasibility - can procedural changes be made to make the system work? Schedule feasibility - can the project be completed by an acceptable time period?
- 13. Project Request
- 17. 3.System Analysis Analysis is the detailed study of the various operations performed by the system and their relation ships within and outside the system The objective of this phase is to determine -What must be done to solve the problem? Understand the existing system The information needs of the organization and its end users. Two tasks are involved Data gathering Data analysis
- 18. Data Gathering A number of techniques can be used ◦ Interviews with users and managers Structured interview – includes only questions that have been written out in advance Unstructured interview – interviewer has a general goal but few, if any questions prepared ◦ Examining current business and systems documents and output may include current order documents, computer systems procedures and reports used by operations and senior management ◦ Sending out questionnaires ◦ Observation of current procedures by spending time in various departments; a time and motion study can show where procedures could be more efficient, or to detect bottlenecks
- 19. Data Analysis Typical tools for data analysis ◦ Entity Relationship diagram ◦ Data flow diagram ◦ Decision table/Decision Tree ◦ Written report Report to management/ customer/ client
- 20. Data Flow Diagrams (DFD) Tool to graphically represent the flow of data in a system Data Store
- 22. System Requirements & recommendations A detailed list of things the system must be able to do ◦ Highlight problems with current system ◦ The design of the new system will be based on these requirements ◦ Analyst and management must come to a clear agreement on requirements ◦ List of possible solutions ◦ Hardware/software recommendations
- 23. Report to Management Summarizes the problems found in the current system Describes the requirements for the new system, including a cost analysis Makes a recommendation on what course to take next
- 24. Pre-Design considerations The hardware platform which type of computer, network capabilities, input, storage and output devices The software programming language, package or database The outputs report layouts and screen designs The inputs documents, screen layouts, validation procedures The user interface how users will interact with the computer system The modular design of each program in the application The test plan and test data Conversion plan how the new system is to be implemented Documentation User Technical
- 26. 4.System Design System Analysis describes WHAT the system should do to meet the information needs of users? System Design describes HOW the system will accomplish this objective? “Design” refers to the technical specifications that will be applied in construction of a system How should the problem solved?(it stresses on following activities) 1. User Interface (interactions between user & computer systems) 2. Data design (Logical structure of database and files) 3. Process design. (Software design) ‘The design must specify what type of H/W, S/W and people resources will be needed’
- 27. Design The new system is actually planned Divided into two sub phases Preliminary design Several key decisions must be made Detail design specifications Output requirements Input requirements Files and databases System processing System controls and backups
- 28. Build or Buy? Custom Software ◦ Developed by user ◦ Developed at user request by outside vendor Packaged Software ◦ Horizontal Many org types ◦ Vertical Industry specific
- 29. Acquire Hardware/Software Technical specifications Solicit vendor proposals Test & evaluate ◦ Benchmark Test Make a decision
- 30. Input Output Things to consider ◦ The medium (paper, screen, etc.) of the output ◦ The types of reports needed and what data is needed for the reports Things to consider ◦ The input medium (captured at the source, keyed from source document) ◦ The fields needed, how they are laid out on the input screen, etc. ◦ Input validation may be necessary Requirements
- 32. Files and Databases Things to consider ◦ How files are organized Sequentially, directly, or by another method ◦ The format of the records making up the data files
- 33. Database Design Table structure definitions & relationships Security
- 35. Phase 4: Development Schedule and monitor the two principal activities Programming Testing There are several project scheduling tools available
- 36. Programming Prepare program design specifications Use logic flowcharts and pseudocode to facilitate code development
- 37. Gantt chart
- 38. Pert chart
- 39. Testing Unit testing – verifies that individual program units work ◦ Perform testing with test data System testing – determines whether all program units work together as planned Volume testing – uses real data in large amounts ◦ Determines whether the system can handle a large volume of data
- 41. Phase 5: Implementation Steps involved in starting the new system Training Equipment conversion File conversion System conversion Auditing Evaluation Maintenance
- 42. Training Teach users how to use the system ◦ The system will do no better than the people using it ◦ Develop user’s manual to aid users who are not familiar with the system ◦ Hands-on training is best
- 43. Equipment Conversion Items to consider ◦ Delivery schedules must be coordinated ◦ Terminals or personal computers must be networked ◦ Devices on the system must be compatible
- 44. File Conversion If existing files are manual, they must be keyed in or scanned into the system ◦ Manual files must be kept current while data is being input into the new system If existing files are computer-based, programs must be written to convert the files into the format needed for the new system
- 45. System Conversion Four approaches ◦ Direct conversion – the user simply stops using the old system and starts using the new one ◦ Parallel conversion – the old and new systems are both used until users are satisfied with the new system works ◦ Phased conversion – the system is implemented one part at a time ◦ Pilot conversion – the entire system is used by a designated set of users
- 48. Evaluation Determines how well the system is meeting the original requirements, benefits, and budgets ◦ Evaluation can be performed by the analyst and someone from the organization ◦ Evaluation can also be performed by an independent third party
- 49. Maintenance The emphasis during this phase is to ensure that needs continue to be met and that the system continues to perform according to specifications. Routine hardware and software maintenance and upgrades are performed to ensure effective system operations. User training continues during this phase, as needed, to acquaint new users to the system or to introduce new features to current users.
- 50. Role of the Accountant in SDLC • How can accountants be involved in all stages of the SDLC? •In the planning stage, accountants provide some of the information used to evaluate the feasibility of the proposed project and participate in making that decision.
- 51. Role of the Accountant In the requirements Analysis and Design stages, Accountants participate in identifying user information needs, developing the logical and physical models and specifying controls. Accountants with good IT skills may participate in the coding stage.
- 52. Role of the Accountant During the implementation stage, accountants are involved in testing the accuracy of the new database and the application programs that will use that data. Finally, accountants use the database system to process transactions