What is the module about?

1. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk What is the module about? • As you can see from the schedule this is a practical module • New skills! • It must be underpinned with background reading and wider SE practice where directed • As always we only have 12 weeks and so do not get overwhelmed by the subject matter

2. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Skills include • A summary of the software engineering skills to impart to you:- • How to program using OO software engineering techniques • OO Web development skills • Awareness and use of object oriented methods (UML) • Database integration • Good practice

3. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk In context • Other aspects of software engineering are covered by other modules • Project management/Systems Analysis/Communications/Computer hardware and software • All the above topics come under the umbrella of software engineering • can seem confusing until you realise that software engineering involves a set of stages and tools

4. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk SE scope • We need to understand what software engineering is and how it came about • Why use it? • How to use it - the lifecycles • Improvements • Future of software engineering

5. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk What is SE? • An approach to software development to embody the same discipline and rigor found in the engineering world • Advantages include: • Speed/productivity improvements • Re-use of existing, well-tested subsystems • Measurable outcomes

6. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk History 1 • The “software crisis”, recognised C1969. - threatened the progress of the computer industry • People-time was and still is relatively expensive, machine-time is now very cheap. • Programming was and still is very time intensive. • Products need support - probably more than ever • Software is complex; imagine creating a car with no drawings, specifications or planning. • Software “lives” – it somewhat “erodes” with age – contexts, details, standards and usage change

7. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Trends • The price of computer hardware is still falling fast • The cost of computer software is still high • More and more products are incorporating microprocessors (and thus software),e.g car engines, cameras, TV sets and mobile phones • Hundreds of millions of personal computers are in use, often in strategic roles.

8. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Trends • Personal, corporate, national and international economies are increasingly dependent on computers, computer-mediated communication and software systems • Some commercial software is still written in old COBOL (and new Object Cobol!) and has been modified and patched by generations of engineers • Some of our most complex feats of engineering are computer programs

9. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Programming; Development • Programming is much more than just writing code. • Programming involves (at least) the following activities;- • Problem analysis, • Planning, • Code and interface design, • Coding, Debugging and Testing, • Documenting each activity. • Do you all agree?

10. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk And incorporates documentation • Documentation is more than just a listing of the finished program. • Documentation involves all of the following;- • Records of the analysis of the problem, • The time & resource plan, • Technical and User documents, • Records of all bugs and bug fixes, • Records of test input and output.

11. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk The people aspect • IT personnel now expected to have a range of skills • There are many different roles with a software development project • People may join or leave a development team, roles can change

12. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Top ten IT skills lists • www.sap-img.com, 20101. J2EE 2. .Net 3. C# 4. Project Management 5. Oracle 8 and 9i 6. SAP 7. Business Analysis 8. VB.net 9. NT Novell 10. Other non-J2EE Java • careerfruits.com SiliconIndia, 2010SAPJavaC++PHPIT Infrastructure Management Oracle.NetEmbedded C++CMobile Java/C

13. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Software Development Lifecycles. • Software engineering helps to co-ordinate the team so that they are “on the same page” • How does it help? • Lifecycles • Automation of tasks • Since the software crisis of the 70’s, software developers have been looking for a solution… • to increase programmer productivity • to increase the quality of software • to decrease software production costs • Why? Because industry (the users) were fed up waiting for software and because it was costly

14. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Software DevelopmentLife Cycle(SDLC) - Classical • Software Engineering has identified several classical life cycles with different complexities, different aims and different outcomes. • Its up to you which one you choose and can of course be a combination of more than one • SDLCs include (see tutorial session for links) • Cyclic • Waterfall/Cascade • Evolutionary • ‘V’ • DSDM

15. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Nature of SDLCs • All life cycles describe a process that you use to produce software • They are practical and are worth employing? <discuss> • You need to have some understanding of all of them • They all have common features - stages • Systems Analysis and Design or Requirements engineering module typically involves a couple of stages in the software development life cycle

16. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Cyclic • Cyclic features • Easy to use • Useful for bespoke/one off systems with no maintenance • No definitive start or finish to the process • Includes a recognition of management involvement • Can be difficult to control

17. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Cyclic Idea for a project or product Contract for a Project Concepts/ Feasibility Requirements/ Specification Management yes/no Next version Design and Code Testing and Acceptance Maintenance

18. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Waterfall • One of the most famous SDLC’s - a waterfall because the stages of the lifecycle follow the premise of one stage following another • Still shows a somewhat cyclic nature to software development. • Shows the possibility of rework. • Includes maintenance as a vital part of the cycle. • No inbuilt control or management recognition (a weakness)

19. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk SDLC (waterfall) System/Software Requirements Analysis Design Code Test Release Maintenance

20. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Evo • The Evolutionary life cycle is quite different from most other cycles. • Tom Gilb is credited with this SDLC • It’s main principle is that of the surrounding environment and therefore the requirements continually change!/evolve • Therefore an SDLC must reflect this position • Evo produces many small steps/ products towards an overall goal. • It is VERY difficult to control. • Many people argue that it is the ONLY way to achieve a quality product

21. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Evo • Evo’s guiding principles are :- • Deliversomething to a real end-user • Measurethe added-value to the user in all critical dimensions • Adjust both design and objectives based on observed realities.

22. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Evo Evolutionary Life Cycle. initial objectives revised course towards new objectives heading towards initial objectives useful delivery to user steps changed objectives

23. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk ‘V’ • The ‘V’ life cycle is an extension of the waterfall life cycle. • It includes elements of Quality Assurance at every stage. • Looks at the whole of the project • No obvious management, but inbuilt control through QA.

24. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk ‘V’ Maintenance Requirements Acceptance Test Analysis System Test High level Design Integration Test Low level Design Module Test Code Unit Test V Life Cycle

25. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Conclusion • Software Development life cycles describe the process used to produce software. • Questions to always ask: • What does it achieve? • What doesn’t it achieve? • How could you alter it to be better?

26. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Insight – ability to reflect • You must identify your life cycle. • You must identify the requirements for your life cycle • You should look at possible ways to improve it. • Question :- Should there be one life cycle for the team/project? • What are the benefits and problems of such a suggestion? • What are you going to do about it?

27. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk Conclusion contd • As we have discussed - some of the life cycles don’t include recognition of project management and control • Project management and control is CRUCIAL and you will find in industry/books reference being made to the Project Development Life Cycle(PDLC) • The SDLC fits inside a PDLC - it is the life cycle for the software development part of the project(of course that may be the whole of the project)

28. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk The complete software developer? • A Software Engineer! • SE includes both technical and non-technical elements, so software engineers must be able to communicate well, both orally and in writing. • They must have a thorough knowledge of computer systems and must understand the importance of project management, user feedback, documentation and quality control • So easy ….!!!

29. j.c.westlake@staffs.ac.uk, n.a.shulver@staffs.ac.uk The future • SE still as relevant today as it was in 1970 • Tools have changed and will continue to do so • CASE tools have had limited success - specialised tools tend to be used for each stage • Modelling, Design, Testing, Optimisation etc. • UML is interesting as it is universal • New sets of challenges appeared in the latter part of the 1990’s - web development – we will look at this later on in the module when we cover JSP • Requirements capture as important as ever for the success of a project….this has not changed in being still the area most prone to getting it wrong • Still evidence of projects failing however…..why? <discuss>