1 / 59

SE 501 Software Development Processes

SE 501 Software Development Processes. Dr. Basit Qureshi College of Computer Science and Information Systems Prince Sultan University. Lecture for Week 3. Contents. SDLC’s continued Agile, RUP, TSP, ACDM Choosing suitable SDLC Summary Discussion on Assignment #2. Bibliography.

yahto
Download Presentation

SE 501 Software Development Processes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SE 501 Software Development Processes Dr. Basit Qureshi College of Computer Science and Information Systems Prince Sultan University Lecture for Week 3

  2. Contents • SDLC’s continued • Agile, RUP, TSP, ACDM • Choosing suitable SDLC • Summary • Discussion on Assignment #2 SE 501 Dr. Basit Qureshi

  3. Bibliography • Humphrey, Watts (1999). Introduction to the Team Software Process. Addison Wesley. • http://www.ibm.com/developerworks/rational/library/1826.html#N100E4 • Justin Rockwood, “Choose Your Weapon Wisely” CMU, 2003 • Larman, Craig (2004). Agile and Iterative Development: A Manager's Guide. Addison-Wesley • Lattanze, Anthony J. (2009). Architecting Software Intensive Systems: A Practitioners Guide. Software Engineering. CRC Press SE 501 Dr. Basit Qureshi

  4. SDLC Continued SE 501 Dr. Basit Qureshi

  5. SDLC continued • Last week • Ad Hoc • Classical (Water fall) • Prototype • RAD • Incremental • Spiral • WinWin • V model • Chaos SE 501 Dr. Basit Qureshi

  6. SDLC: More recent • Agile • RUP • TSP • ACDM SE 501 Dr. Basit Qureshi

  7. SDLC: More recent SE 501 Dr. Basit Qureshi

  8. Agile methods Webster Dictionary: “Marked by ready ability to move with quick easy grace” As applied to Software Development: Cockburn “Ability to change development in response to changing requirements” SE 501 Dr. Basit Qureshi

  9. Agile methods The Agile Manifesto [http://agilemanifesto.org/] “A method of software development that aims for customer satisfaction through early and continuous delivery of useful software components” SE 501 Dr. Basit Qureshi

  10. Agile methods • Rapid development and delivery is now often the most important requirement for software systems • Businesses operate in a fast –changing requirement and it is practically impossible to produce a set of stable software requirements • Software has to evolve quickly to reflect changing business needs. • Rapid software development • Specification, design and implementation are inter-leaved • System is developed as a series of versions with stakeholders involved in version evaluation • User interfaces are often developed using an IDE and graphical toolset. Chapter 3 Agile software development

  11. SE 501 Dr. Basit Qureshi

  12. Agile methods • Dissatisfaction with the overheads involved in software design methods of the 1980s and 1990s led to the creation of agile methods. These methods: • Focus on the code rather than the design • Are based on an iterative approach to software development • Are intended to deliver working software quickly and evolve this quickly to meet changing requirements. • The aim of agile methods is to reduce overheads in the software process (e.g. by limiting documentation) and to be able to respond quickly to changing requirements without excessive rework. Chapter 3 Agile software development

  13. Agile manifesto • We are uncovering better ways of developing 
software by doing it and helping others do it. 
Through this work we have come to value: • Individuals and interactions over processes and toolsWorking software over comprehensive documentation Customer collaboration over contract negotiationResponding to change over following a plan • That is, whilethere is value in the items on 
the right, we value the items on the left more. Chapter 3 Agile software development

  14. The principles of agile methods Chapter 3 Agile software development

  15. Agile method applicability • Product development where a software company is developing a small or medium-sized product for sale. • Custom system development within an organization, where there is a clear commitment from the customer to become involved in the development process and where there are not a lot of external rules and regulations that affect the software. • Because of their focus on small, tightly-integrated teams, there are problems in scaling agile methods to large systems. Chapter 3 Agile software development

  16. Plan-driven and agile development • Plan-driven development • A plan-driven approach to software engineering is based around separate development stages with the outputs to be produced at each of these stages planned in advance. • Not necessarily waterfall model – plan-driven, incremental development is possible • Iteration occurs within activities. • Agile development • Specification, design, implementation and testing are inter-leaved and the outputs from the development process are decided through a process of negotiation during the software development process. Chapter 3 Agile software development

  17. Plan-driven and agile specification Chapter 3 Agile software development

  18. Agile methods • XP • Scrum • Crystal • Feature Driven • Open Source • Software Develop • RUP (AUP) • Dynamic Systems • Develop Method • Adaptive Software • Develop • Synch and stabilize SE 501 Dr. Basit Qureshi

  19. Agile methods Common characteristics • Individuals and Interactions over Processes and Tools • Team dynamics • experience mix, team size • Physical workspace, communality, meetings • Working Software over Comprehensive Documentation • Code primary artifact • Iterative (subscription) • Value to the customer • QA inherent SE 501 Dr. Basit Qureshi

  20. Agile methods • Customer Collaboration over Contract Negotiation • Customer Onsite (Involved/Knowledgeable) • Requirements Centric • Rapid Return of Perceived Value • Customer Expectation Management • Responding to Change over Following a Plan • Developer / Customer Team • Emergent Requirements • Short Iterations • Smaller changes • Adaptation SE 501 Dr. Basit Qureshi

  21. Why Agile methods What agile proponents say: • Flexibility • Market Changes • Technology Changes (Moore’s Law) • Unclear Requirements • More coding, less paper-work • Higher quality, quicker SE 501 Dr. Basit Qureshi

  22. Why Agile methods What the opponents say: • No plan, no structure • Architecture? • Easily derailed • Inefficient use of developers • pair programming • No documentation • Unrealistic customer involvement SE 501 Dr. Basit Qureshi

  23. Why Agile methods “More than 2/3’s of all corporate IT organizations will use some form of agile software development process in the next 18 months.” Giga Information Group Inc., 2002 • Cutter Report “Agile vs. Heavy” • Use is increasing SE 501 Dr. Basit Qureshi

  24. Why Agile methods And now.. Chaos Report published in 2012. • 49% of businesses say most of their company is using Agile development • 52 % of customers are happy or very happy with Agile projects • The number of those who plan to implement agile development in future projects has increased from 59% in 2011 83% in 2012. • The most popular Agile method used is Scrum (52%) SE 501 Dr. Basit Qureshi

  25. Weakness of Agile methods • Communication is critical • Projects with Non- Decomposability / Coupled Functionality • Scalability • Reliance on Corporate Knowledge • – Document at End • Maintenance • Long Life Cycle SE 501 Dr. Basit Qureshi

  26. Weakness of Agile methods • Centralized management control • “Big” Specifications • Required Documentation • Safety Critical • Non-flexible work environment • Fixed Price and Scope SE 501 Dr. Basit Qureshi

  27. Agile methods • Agile center piece: Coding • Emphasizing what we do best • What we prefer to do • Lack of formal design, architecture • Lack of documentation • But makes you think about what is important SE 501 Dr. Basit Qureshi

  28. Agile methods Some Agile methods users • Microsoft • Thoughtworks • ValtechTechnologies • RADsoft • Boeing • < 5 on a team • Al Elm Information Security • Arabian Electronics Co SE 501 Dr. Basit Qureshi

  29. RUP SE 501 Dr. Basit Qureshi

  30. RUP • The Rational Unified Process (RUP) is an iterative software development process framework created by the Rational Software Corporation, a division of IBM since 2003 • RUP is not a single concrete prescriptive process, but rather an adaptable process framework, intended to be tailored by the development organizations and software project teams that will select the elements of the process that are appropriate for their needs SE 501 Dr. Basit Qureshi

  31. RUP • Four project lifecycle phases • Inception Phase: • Stakeholders, Requirements understanding, cost/schedule estimates, architectural prototype, compare actual expenditures versus planned expenditures. • Elaboration Phase: • Most of the use-case descriptions are developed (80%), software architecture, development plan for the overall project, Business case and risk list. • Construction Phase • Build the software system, Software Release. • Transition Phase • Transit from development to production, training, testing SE 501 Dr. Basit Qureshi

  32. RUP Outline – Phases vs iterations SE 501 Dr. Basit Qureshi

  33. RUP Strengths: • Structured • Iterative • Use Cases – strong concept, used widely • Tied to UML • Robust tool support • Tailor-able / Scalable • “Agile” ? SE 501 Dr. Basit Qureshi

  34. RUP Weaknesses • Use cases – do they work for all projects? • Learning curve • Tied to tools • UML • Architecture? • Non functional requirements • Quality Attributes? SE 501 Dr. Basit Qureshi

  35. RUP Center piece: Model analysis • Modeling allows stakeholders to understand the problem • Great for functionality • Not so good for Quality Attributes SE 501 Dr. Basit Qureshi

  36. PSP / TSP • Personal Software Process (PSP) 1989’ • structured software development process that is intended to help software engineers understand and improve their performance, by using a "disciplined, data-driven procedure" • Team Software Process (TSP) 2000’ • designed to help teams of managers and engineers organize projects and produce software products • The initial version of the TSP was developed and piloted by Watts Humphrey in the late 1990s SE 501 Dr. Basit Qureshi

  37. PSP / TSP • Builds on Personal Software Process (Pre-requisite) Prevent defects earlier • Defined framework - Scripted • Cyclic, iterative • Standard measures for quality and performance • Precise data collection- on almost everything • Established Roles • Discipline and guidance • Post Mortem each cycle – find the problems • CMM… SE 501 Dr. Basit Qureshi

  38. PSP / TSP Every cycle produces an artifact A Team Software Process Cycle: 1- Strategy 2- Plan 3- Requirements 4- Design 5- Implementation 6- Test 7- Postmortem SE 501 Dr. Basit Qureshi

  39. PSP / TSP TSP is document driven • The “Good” of TSP • Structured • Scripted • Highly defined • New teams, or ones with no structure • SEI has data on about 20 projects • The “other” • Possible problems with change/flexibility • Requirements? • Documentation SE 501 Dr. Basit Qureshi

  40. PSP / TSP • TSP centerpiece: Data Collection • Only source of “bugs” is humans • Developers on the whole are unstructured and tend towards “hacking” • Need to identify source and mitigate problem SE 501 Dr. Basit Qureshi

  41. PSP / TSP users • U. S. Navy • Microsoft • Xerox • Bechtel – Bettis • Advance Information Systems SE 501 Dr. Basit Qureshi

  42. ACDM • Architecture Centric Development Method • ACDM is an iterative development method • iteratively refines and reviews the architecture until it is deemed fit for the purpose • permits iteration in the production of the elements/system/products • ACDM has 7 stages in the development method. • ACDM proposed by Anthony J. Lattanze of the of SEI at CMU, 2009. SE 501 Dr. Basit Qureshi

  43. ACDM SE 501 Dr. Basit Qureshi

  44. ACDM Strengths: • Product and Architectural focus. • Agile and relatively lightweight. • Structured but flexible and tailorable. • Iterative. • Derived from Studio Practitioners. • Provides guidance for roles, activities, and artifacts. • Derives requirements (architectural drivers) from business drivers. SE 501 Dr. Basit Qureshi

  45. ACDM Weaknesses: • Not a lot of industrial experience or data. • Unclear how well ACDM scales up to large projects. • Still maturing. • No tool support or templates. • Depends upon a relatively good understanding of architectural concepts. SE 501 Dr. Basit Qureshi

  46. ACDM Centerpiece: Architecture • Complexity/scope driving need for more abstraction • Key to describing and predicting quality attributes • Lots of development and research • Easily misunderstood SE 501 Dr. Basit Qureshi

  47. Choosing suitable sdlc SE 501 Dr. Basit Qureshi

  48. Choosing suitable SDLC • Looking for a recipe… . • There is no silver bullet • Do not tailor your project to a process, instead tailor the “right process” • Supermarket shopping • Do not pick all the “best” techniques within processes and mix them together • But you can use some in tailoring SE 501 Dr. Basit Qureshi

  49. Choosing suitable SDLC SE 501 Dr. Basit Qureshi

  50. Choosing suitable SDLC • “Choose Your Weapon Wisely” Justin Rockwood 2003. • Describes a weighted matrix model • Weakness • Push • Strength • Compares suitability of 5 methods • RUP • MS Synch and Stabilize • TSP • XP • Scrum SE 501 Dr. Basit Qureshi

More Related