Lect6 life cycle phases
- 1. Unit-2 Life cycle phases Dr Meena Malik(meenamlk@gmail.com)
- 2. Software Development Process A successful software development process must define separation between "research and development" activities and "production" activities. Major factors for unsuccessful projects are: • Overemphasis on research and development • Overemphasis on production. • Successful modern as well as conventional process must express well-defined project milestone and a noticeable transition from a research to production • Earlier phases focus on achieving functionality. • Later phases focus to achieve a product that can be shipped to a customer, with explicit attention to robustness, performance, and finish. .
- 3. Modern Software Development Process A modern software development process must be defined to support the following: • Evolution of the plans, requirements, and architecture, together with well defined synchronization points • Risk management and objective measures of progress and quality • Evolution of system capabilities through demonstrations of increasing functionality
- 5. ENGINEERING & PRODUCTION STAGES To achieve economies of scale and higher ROI, we must move toward technological improvements in process automation and component-based development. Two stages of the life cycle are: 1. The engineering stage, driven by less predictable but smaller teams doing design and synthesis activities 2. The production stage, driven by more predictable but larger teams doing construction, test, and deployment activities
- 6. • The transition between engineering and production is a crucial event for the various stakeholders. • The production plan has been agreed upon, and there is a good enough understanding of the problem and the solution that all stakeholders can make a firm commitment to go ahead with production. • Engineering stage is decomposed into: • Inception • Elaboration, • Production stage is decomposed into: • Construction • Transition.
- 7. • four phases of the life-cycle process are loosely mapped to the conceptual framework of the spiral model
- 8. 1. INCEPTION PHASE Goal is to achieve concurrence among stakeholders on the life- cycle objectives for the project. PRIMARY OBJECTIVES : • Establishing the project's software scope and boundary conditions, including an operational concept, acceptance criteria, and a clear understanding of what is and is not intended to be in the product • Discriminating the critical use cases of the system and the primary scenarios of operation that will drive the major design trade-offs • Demonstrating at least one candidate architecture against some of the primary scenanos • Estimating the cost and schedule for the entire project (including detailed estimates for the elaboration phase) • Estimating potential risks (sources of unpredictability)
- 9. 1.1 ESSENTIAL ACTIVITIES • Formulating the scope of the project. The information repository should be sufficient to define the problem space and derive the acceptance criteria for the end product. • Synthesizing the architecture. An information repository is created that is sufficient to demonstrate the feasibility of at least one candidate architecture and an, initial baseline of make/buy decisions so that the cost, schedule, and resource estimates can be derived. • Planning and preparing a business case. Alternatives for risk management, staffing, iteration plans, and cost/schedule/profitability trade-offs are evaluated.
- 10. 1.2 PRIMARY EVALUATION CRITERIA • Do all stakeholders concur on the scope definition and cost and schedule estimates? • Are requirements understood, as evidenced by the fidelity of the critical use cases? • Are the cost and schedule estimates, priorities, risks, and development processes credible? • Do the depth and breadth of an architecture prototype demonstrate the preceding criteria? (The primary value of prototyping candidate architecture is to provide a vehicle for understanding the scope and assessing the credibility of the development group in solving the particular technical problem.) • Are actual resource expenditures versus planned expenditures acceptable .
- 11. 2. ELABORATION PHASE • At the end of this phase, the "engineering" is considered complete. • Here activities must ensure that the architecture, requirements, and plans are stable enough, and the risks sufficiently mitigated, that the cost and schedule for the completion can be predicted within an acceptable range. • Here an executable architecture prototype is built in one or more iterations, depending on the scope, size, & risk.
- 12. 2.1 PRIMARY OBJECTIVES • Baselining the architecture as rapidly as practical (establishing a configuration-managed snapshot in which all changes are rationalized, tracked, and maintained) • Baselining the vision • Baselining a high-fidelity plan for the construction phase • Demonstrating that the baseline architecture will support the vision at a reasonable cost in a reasonable time
- 13. 2.2 ESSENTIAL ACTIVITIES • Elaborating the vision. This activity involves establishing high reliable and understanding of critical use cases that make architectural or planning decisions • Elaborating the process and infrastructure. The construction process, the use of tools and automation support, their respective evaluation criteria is established. • Elaborating the architecture and selecting components. Potential components are evaluated and make/buy decisions are understood so that construction phase cost and schedule can be determined with confidence.
- 14. 2.3 PRIMARY EVALUATION CRITERIA • Is the vision stable? • Is the architecture stable? • Does the executable demonstration show that the major risk elements have been addressed and credibly resolved? • Is the construction phase plan of sufficient fidelity, and is it backed up with a credible basis of estimate? • Do all stakeholders agree that the current vision can be met if the current plan is executed to develop the • complete system in the context of the current architecture? • Are actual resource expenditures versus planned expenditures acceptable?
- 15. 3. CONSTRUCTION PHASE • During the construction phase, all remaining components and application features are integrated into the application, and all features are thoroughly tested. • Newly developed software is integrated where required • The construction phase represents a production process, in which emphasis is placed on managing resources and controlling operations to optimize costs, schedules, and quality.
- 16. 3.1 PRIMARY OBJECTIVES • Minimizing development costs by optimizing resources and avoiding unnecessary scrap and rework • Achieving adequate quality as rapidly as practical • Achieving useful versions (alpha, beta, and other test releases) as rapidly as practical
- 17. 3.2 ESSENTIAL ACTIVITIES • Resource management, control, and process optimization • Complete component development and testing against evaluation criteria • Assessment of product releases against acceptance criteria of the vision
- 18. 3.3 PRIMARY EVALUATION CRITERIA • Is this product baseline mature enough to be deployed in the user community? (Existing defects are not obstacles to achieving the purpose of the next release.) • Is this product baseline stable enough to be deployed in the user community? (Pending changes are not obstacles to achieving the purpose of the next release.) • Are the stakeholders ready for transition to the user community? • Are actual resource expenditures versus planned expenditures acceptable?
- 19. 4. TRANSITION PHASE It Starts when a baseline is mature enough to be deployed in the end-user domain. This typically requires that a usable subset of the system has been achieved with acceptable quality levels and user documentation so that transition to the user will provide positive results. Activities: 1. Beta testing to validate the new system against user expectations 2. Beta testing and parallel operation relative to a legacy system it is replacing 3. Conversion of operational databases 4. Training of users and maintainers • The transition phase concludes when the deployment baseline has achieved the complete vision.
- 20. 4.1 PRIMARY OBJECTIVES • Achieving user self-supportability • Achieving stakeholder concurrence that deployment baselines are complete and consistent with the evaluation criteria of the vision • Achieving final product baselines as rapidly and cost-effectively as practical
- 21. 4.2 ESSENTIAL ACTIVITIES • Synchronization and integration of concurrent construction increments into consistent deployment baselines • Deployment-specific engineering (cutover, commercial packaging and production, sales rollout kit development, field personnel training) • Assessment of deployment baselines against the complete vision and acceptance criteria in the requirements set
- 22. 4.3 EVALUATION CRITERIA • Is the user satisfied? • Are actual resource expenditures versus planned expenditures acceptable?
- 23. References • Software Project management, Walker Royce, Addison Wesley, 1998. • https://www.javatpoint.com/software-project-management