1 Staffordshire UNIVERSITY School of Computing Slide: 1 Prototyping Agile Software Development 2 Agile Methods and Software Architectures

2 Staffordshire UNIVERSITY School of Computing Slide: 2 Prototyping Agenda  Agile Manifesto  Agile Methods  Agile and RAD  Multi-Tier Architectures  Iterative Design  Some Trends  Tutorial Tasks

3 Staffordshire UNIVERSITY School of Computing Slide: 3 Prototyping Agile Manifesto  Formation of the Agile Alliance On February 11–13, 2001, at The Lodge at Snowbird ski resort in the Wasatch mountains of Utah, 17 people met to talk, ski, relax and try to find common ground. What emerged was the Agile Software Development Alliance.  Manifesto for Agile Software Development: We are uncovering better ways of developing software by doing it and helping others do it.  This produced Agile Values and Agile Principles See for example:

4 Staffordshire UNIVERSITY School of Computing Slide: 4 Prototyping Agile Manifesto Agile Values  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 tools  Working software over comprehensive documentation  Customer collaboration over contract negotiation  Responding to change over following a plan  That is, while there is value in the items on the right, we value the items on the left more.

5 Staffordshire UNIVERSITY School of Computing Slide: 5 Prototyping Agile Manifesto Agile Principles (1-3)  Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.  Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.  Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale.

6 Staffordshire UNIVERSITY School of Computing Slide: 6 Prototyping Agile Manifesto Agile Principles (4-6)  Business people and developers must work together daily throughout the project.  Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.  The most efficient and effective method of conveying information to and within a development team is face-to- face conversation.

7 Staffordshire UNIVERSITY School of Computing Slide: 7 Prototyping Agile Manifesto Agile Principles (7-9)  Working software is the primary measure of progress.  Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.  Continuous attention to technical excellence and good design enhances agility.

8 Staffordshire UNIVERSITY School of Computing Slide: 8 Prototyping Agile Manifesto Agile Principles (10-12)  Simplicity – the art of maximizing the amount of work not done – is essential.  The best architectures, requirements, and designs emerge from self-organizing teams.  At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behaviour accordingly.

9 Staffordshire UNIVERSITY School of Computing Slide: 9 Prototyping Agile Methods  Agile methods reduce software lifecycle time (thus speeding up development) by firstly developing a prototype version, then integrating functionality on an iterative basis responding to customer requirements and testing throughout the development cycle  Agile methods originate from the instability of the technical environment and the fact that the client is often unable to define every single requirement at the start of the project. See:

10 Staffordshire UNIVERSITY School of Computing Slide: 10 Prototyping Agile Methods  The term "agile" is a reference to the ability to adapt to contextual changes and changes to specifications which occur during the development process.  With the help of agile methods, the customer is in total control of his project and achieves rapid software implementation.  Thus, this allows for user involvement from the beginning of the project.

11 Staffordshire UNIVERSITY School of Computing Slide: 11 Prototyping Agile Methods  RAD- Rapid Application Development  DSDM- Dynamic Software Development Method  UP- Unified Process  RUP- Rational Unified Process  XP- Extreme Programming

12 Staffordshire UNIVERSITY School of Computing Slide: 12 Prototyping Agile Methods  RAD (Rapid Application Development) was defined by James Martin in the early 1980s, and consists of a short development cycle based on 3 phases (Requirements, Design and Construction) with an ideal delivery time of between 90 and 120 days maximum.

13 Staffordshire UNIVERSITY School of Computing Slide: 13 Prototyping Agile Methods  The DSDM (Dynamic Software Development Method) was developed to fill in some of the gaps in the RAD method by providing a framework which takes into account the entire development cycle.  The main features of the DSDM method are as follows:  User involvement  Iterative and incremental development  Increased delivery frequency  Integrated tests at each phase  The acceptance of delivered products depends directly on fulfilling requirements.

14 Staffordshire UNIVERSITY School of Computing Slide: 14 Prototyping Agile Methods  The UP (Unified Process) method is an iterative and incremental development process which means that the project is cut into very short phases, where a new incremental version is delivered at the end of each phase.  This approach is based on UML modelling for the description of software architecture (functional, applicational and physical), and user case development which outlines user requirements and demands.

15 Staffordshire UNIVERSITY School of Computing Slide: 15 Prototyping Agile Methods  The RUP (Rational Unified Process) is an iterative development method promoted by the Rational Software company, which was bought by IBM.  The RUP method mainly specifies team make-up and time scales as well as a number of document models.

16 Staffordshire UNIVERSITY School of Computing Slide: 16 Prototyping Agile Methods  The XP method (eXtreme Programming) defines a set of best practices for application development in optimal conditions by placing the customer at the centre of the development process, maintaining a close relationship with the customer.

17 Staffordshire UNIVERSITY School of Computing Slide: 17 Prototyping Agile and RAD  Agile and RAD – beware  When many people look at agile development, they see reminders of the "quick and dirty" RAD efforts of the previous decade.  But, while agile development is similar to RAD in terms of speed and flexibility, there's a big difference when it comes to technical cleanliness.  Agile approaches emphasize quality of design, because design quality is essential to maintaining agility.

18 Staffordshire UNIVERSITY School of Computing Slide: 18 Prototyping Multi-Tier Architectures  Some Architecture Development Milestones  Mainframe Computing  PC Workstation and File Server  Client/Server Models See

19 Staffordshire UNIVERSITY School of Computing Slide: 19 Prototyping Multi-Tier Architectures

20 Staffordshire UNIVERSITY School of Computing Slide: 20 Prototyping Multi-Tier Architectures

21 Staffordshire UNIVERSITY School of Computing Slide: 21 Prototyping Iterative Design  Initial Iterative Design  Persevere – don’t skip this initial stage (want to “get on with” the project)  Wireframe  White Screen Prototype  then the two paths (Tech and Design) can diverge

22 Staffordshire UNIVERSITY School of Computing Slide: 22 Prototyping Some Trends  Local developments not National developments?  C-NOMIS  The project began in June But it was not until 2007 that senior officials discovered that C-Nomis was running two years late and that costs had more than doubled from £234m to a projected £690m over the lifetime of the scheme.  NPfIT - Health Service IT  Problems with technology, contracts, timescales, organisational change, and user acceptance have continually dogged the NHS national programme for IT (NPfIT)  Connexions Web sites  Home Office and NHS/NTA Data Capture

23 Staffordshire UNIVERSITY School of Computing Slide: 23 Prototyping Tutorial Tasks  In small groups discuss the requirements for a Membership Organisation Web based Database  Level 1: Public Access (see all organisations)  Level 2: Member Access (additional information & edit information)  Level 3: Staff Access (membership renewals, key contacts)  Level 4: Client Relationship Management Core  Adopt the roles of  Client (Persona & Goals)  Developer (produce wireframe)  Develop an html Wireframe (using Notepad or other)

24 Staffordshire UNIVERSITY School of Computing Slide: 24 Prototyping Agenda Agile Manifesto Agile Methods Agile and RAD Multi-Tier Architectures Iterative Design Some Trends Tutorial Tasks