Software Process Models

1. Software Process Models

16. Development Phase Techniques • Team creation Scrum believes that a development team should perform as a sport team, every team member working independently but towards the same goal. Scrum suggests that a team has a maximum of 6 - 7 members. The team facilitator is called the Scrum master. His/her job is to implement and manage the Scrum process in the project.

17. Development Phase Techniques • The Scrum team as a whole defines the practices, meetings, artifact and terminology of SCRUM for the team, and the Scrum Master ensures adherence to these "norms" identified. • Scrum masters serve a facilitator role and their authority is mostly indirect. • Scrum masters focus most of their time in managing outside interference for the Scrum team and solving outside impediments or ‘Blockers’ that cannot be solved by the Scrum team.

18. Development Phase Techniques • Backlog creation There are 3 types of backlogs: • Product- Acts as a repository for requirements targeted for release at some point. These are typically high level requirements with high level estimates provided by the product stakeholders. • Release- Requirements pulled from the product backlog and identified and prioritized for an upcoming release. The release backlog contains more details about the requirement and low level estimate which are usually estimated by the team performing the work

19. Development Phase Techniques • Sprint - At the beginning of each sprint, the team has sprint planning with an end result being a backlog of requirements/sub-requirements that the team anticipates completing at the end of the sprint. By completing, that means fully coded, tested and documented. These are the items that the team will "Burndown" against throughout the duration of the sprint. The sprint backlog breaks the release backlog requirement into manageable chunks that can be accomplished typically in 8 - 16 hrs.

20. Development Phase Techniques • Project segmentation The whole project gets divided into periods of time with a maximum duration of 4 weeks. One period is called a Sprint and every team gets a backlog to execute within the given Sprint.

21. Development Phase Techniques Scrum meetings • During the sprint, the team conducts daily scrum meetings. • The meetings are held in the same place at the same time every work day. • The meetings don’t last for more than 30 minutes.A scrum master is appointed. • The scrum master is responsible for asking every team member the following three questions:

22. Development Phase Techniques • What have you done since the last scrum meeting? • What has impeded your work? • What do you plan on doing between now and the next scrum meeting? • Conversation is restricted to the team members answering the above questions. • Meetings can be established for immediately after the scrum meeting based on answers to the above questions.The scrum master is responsible for making decisions immediately, if required to remove impediments to progress. • The scrum master is responsible for noting impediments that must be resolved external to the meeting and causing them to be removed.

23. Development Phase Techniques • Phases The Scrum development process consists of 5 major activities “Review release plans”, “Distribution, review and adjustment of product standards”, “Sprint”, “Sprint review” and “Closure”.

24. Development Phase Techniques • Sprint The Sprint phase is where the software development takes place. A Sprint consists of the following sub-activities: Develop, Wrap, Review and Adjust. This phase has no sequence. Sometimes a backlog item must be developed, wrapped and reviewed and sometimes a backlog item must be only reviewed or adjusted. It totally depends on the backlog item

25. Development Phase Techniques • Sprint review Each Sprint is followed by a Sprint review. During this review the software developed in the previous Sprint is reviewed and if necessary new backlog items are added. The reviewers consist of project stakeholder, managers, developers and sometimes customers, sales and marketing.The activities, Sprint and Sprint review are repeated until the product is deemed ready for distribution by the project stakeholders. Then the project goes into the closure phase where the product is made ready for release and distribution.

26. Development Phase Techniques • Closure In this stage activities like last debugging, marketing and promotion take place. By finishing this activity the project is closed. Because of the unpredictability of the software development process it’s not possible to define exactly when this activity will take place and so the project may take shorter or longer than planned. But by using the controls given by Scrum one can make calculations on the duration of the project.

33. The Unified Process (UP) inception

34. The Unified Process (UP) • A framework for OO SE using UML • Has its roots in the industrial experience within Ericsson • Successor methodologies led by Rational and Objectory • Status: a widely adopted industrial standard • Uses the Unified Modeling Language (UML) • Several OOA and OOD methods were proposed during the 80’s and early 90’s • UP combine the best features of each individual method. • Rational Corporation developed automated tools to support UML methods.

35. The Unified Process (UP) - Phases • Inception (feasibility study) • Document a vision of the product • Who are the expected users of the system • What is the preliminary high-level architecture of the system • What is the development plan and what are the development costs? • Elaboration • Use cases are specified in detail • Software architecture is developed and specified • Construction– developing and testing code • Transition – corresponds to beta testing. • Production – deployment, monitored use of software

36. UP Phases

37. UP Work Products

38. Personal Software Process (PSP) • The Personal Software Process (PSP) is a structured software development process that is intended to help software engineers understand and improve their performance, by using a "disciplined, data-driven procedure"

39. Personal Software Process (PSP) The PSP aims to provide software engineers with disciplined methods for improving personal software development processes. The PSP helps software engineers to: • Improve their estimating and planning skills. • Make commitments they can keep. • Manage the quality of their projects. • Reduce the number of defects in their work. The goal of the PSP is to help developers produce zero-defect, quality products on schedule. Low-defect and zero defect products have become the reality for some developers and TSP teams, such as the Motorola division in Florida that achieved zero defects in over 18 projects through implementing PSP techniques.

40. Personal Software Process (PSP) Recommends five framework activities: • Planning • High-level design • High-level design review • Development • Postmortem Stresses the need for each software engineer to identify errors early and as important, to understand the types of errors

41. Team Software Process (TSP) • In combination with the Personal Software Process (PSP), the Team Software Process (TSP) provides a defined operational process framework that is designed to help teams of managers and engineers organize projects and produce software products that range in size of sizes beyond from small projects of several thousand lines of code (KLOC) to very large projects greater than half a million lines of code. • The TSP is intended to improve the levels of quality and productivity of a team's software development project, in order to help them better meet the cost and schedule commitments of developing a software system.

42. Team Software Process (TSP) • Each project is “launched” using a “script” that defines the tasks to be accomplished • Teams are self-directed • Measurement is encouraged • Measures are analyzed with the intent of improving the team process

43. The Primary Goal of Any Software Process: High Quality Remember: High quality = project timeliness Why? Less rework!