CS 501: Software Engineering

1. CS 501: Software Engineering Lecture 27 Risk in Software Engineering

2. Administration

3. Professionalism: Planning for the Final Presentation • Questions for every presentation • Who is the audience? What do they want? • 2. What do you want to achieve? • How much time do you have? How much can you cover? • What facilities are in the room? Who should be there? • What materials should you prepare? • Do you need a rehearsal?

4. Who is the Audience? What do they Want? Clients The clients have invested effort in this project: • Is it ready for production? • Should they invest more effort to bring it into production? • Should they abandon the project? Course team • What has been accomplished? What has been learned? • Is the client satisfied? • Are you handing over a maintainable system?

5. What do You want to Achieve? • Personal and team satisfaction in handing over a good piece of work to the client • Complete the course in good style with good grade • A clean handover without loose ends Perhaps: a good basis for future involvement with the client, team, or this project

6. How much Time do You Have?How much can You Cover? Plan for 45 minutes total. You should cover: Presentation: • Brief review of goals • Honest summary of achievements and gaps • Summary of what is being delivered Demonstration of operational system: • Show the system in operation • Be honest about gaps, weaknesses, etc. Time for discussion

7. What Materials should you Provide? When you leave, all that the client has is your documentation and your software. Imagine that you work for the client and are asked to take over this system. You would want: • An overview that describes the system goals, architecture, state of implementation and future work • Documentation of requirements and design • Source code, installation instructions and information about installed system • User instructions • Business documentation Materials can be in any form, need not be huge, but must be current.

8. Do you need a Rehearsal? You need a rehearsal • Will you have a single presenter, a moderator, or with each presenter handing to the next? • Decide on the running order of the presentation and stick to it. • When will you take questions? • How will manage the time? Who will take notes? Do not change the system after the rehearsal !

9. Failures and Risks Software development projects can fail in many ways: Bad software engineering • Late, over budget • Lack of function, full of bugs, bad performance Changing circumstances • Changing markets • Better alternatives • Changes of management The biggest single source of problems is poor understanding of requirements

10. Managing Risk Manage projects to avoid risk: • Open and visible software process => Avoid surprises • Continual review of requirements • Willingness to modify or cancel projects

11. Canceling a Project Example: Andrew Window Manager (wm) • Technically superior to X (MIT's Athena project) in 1986 but ... Digital Equipment Corporation turning X into a product with massive support nobody ready to support wm • Therefore wm cancelled in 1986, Andrew user interface and applications ported to X

12. Failure to Cancel a Project Example: University F developed a novel programming language. • From 1985 to 1989, this was a promising language for simple programming of window-based applications • By 1990, it clearly not gaining acceptance beyond University F • But development continued for many more years (about $500K) Not cancelled because ...

13. Too Big to Cancel! Example: University A has antiquated administrative systems. Senior management decides to replace them all with commercial packages from X. The timetable and budget are hopelessly optimistic. • Staff get dispirited. • The Chief Information Officer finds another job. • A new Chief Information Officer is appointed. What should she do?

14. We are doing it the Wrong Way! Example: University B has a (big) joint project with Company Y to develop a new computer operating system. After two years work, a junior software developer persuades the university leader that the technical approach is wrong. • What should the university do? • What should the company do?

15. How to Stop Gracefully • It is harder to cancel a project than to start it. • It is harder to withdraw a service than introduce it. Considerations • The proponents of the system must now reverse their public stance. => Management of expectations • Users of the service need a migration strategy. • Technical staff must have a graceful path forward.

16. Time to Complete a Software Project Large software projects typically take at least two years from start to finish • Formative phase -- changes of plan are easy to accommodate • Implementation phase -- fundamental changes are almost impossible Yet many things can change in two years.

17. A Sense of Urgency Example: A not-for-profit corporation is developing a system for a government organization. • By 1996 all research had been completed and the system demonstrated successfully with real users. • In 2004, the system is still not in full production Reasons: => Incremental improvements to the software => Repeated requests for more functionality => Reluctance to reorganize clerical staff Nobody had a sense of urgency

18. Overtaken by Events Example: University C has a project to develop a digital library system, with funds from Company Z , private foundations and the government. • By 1993 an extensive system is running at the university and Z is marketing the technology to its customers. • By 1994 it is clear that web browsers and web formats (though technically weak) are becoming widely adopted. => What should the university do? => What should the company do?

19. Changing Requirements and Design Example: The CNRI Handle System -- a high performance, distributed system to map names to resources (1994 - ). Design decisions made in 1994 had to be changed. • In 1994 only Web browser was Mosaic • In 1994 Java did not exists • In 1994 mirroring and caching utilities were not available • In 1994 commercial interest was limited Software was rewritten and greatly improved in 1998/9. In 2004, it is widely used by publishers (as DOI) and libraries. If a job's worth doing, it's worth doing twice!

20. Changes of Leadership Many projects are wasted because of management changes Example: In 1988, Company W gave University D $1,000,000 to port a new operating system to its personal computers. The work was well done, on time. • Company W changed its president and senior technical staff during the project. The work was wasted. • A decade later and several presidents later, Company W is building its future around a modern version of the same operating system. A graduate student from University D is now Senior Vice President of Company W!

21. Client Oversight When work is out-sourced, the client must be vigilant. Example: Company G was the world's leader in software for optimization (e.g., linear and integer programming). G had implemented several packages for various manufacturers. • An computer company H contracted with G to develop an optimization package for its new operating system. • The package was late, performed badly and disliked by customers. What went wrong? What can we learn?

22. Too Difficult! A development team at University E was given government funds to build a high-performance gateway from protocol x to protocol y. • A promising young developer was hired and assigned to this task • The project was too difficult for him, but he hid his problems for many months. • The project produced nothing of value. What can we learn from this experience?

23. Accept the Obvious! Six organizations were funded by the National Science Foundation, for one year, to develop demonstration projects. The National Science Foundation hoped that the six organizations would then submit a multi-million, five year proposal to develop the production system together. but ... there were differences (technical and personal) between the organizations. Three weeks before the proposal was due, the principal investigator at University Q decided that the plan was doomed to failure. What should he do?

24. Engineering and Marketing Corporate engineering & marketing divisions at cross purposes: Examples: • Xerox's Palo Alto Research Center pioneered window managers, Ethernet, graphical user interfaces, font managers, etc, => Apple, Adobe, Digital, etc. brought them to the market • IBM would not bring its first Unix workstation to the market until the software had been largely rewritten => Sun's early workstations were unreliable but sold well

25. Senior Management Dynamics • Directors and shareholders appoint the President => The President does not want to admit failures • The President appoints the Chief Information Officer => The CIO does not want to admit failures • The CIO appoints the computing managers => The computing mangers do not want to admit failures • The computing managers appoint the developers => The developers do not want to admit failure Everybody pretends that things are going well

26. Senior Management Dynamics At last the troubles can not be hidden ... • Directors and shareholders try to blame the President • The President tries to blame the Chief Information Officer • The CIO tries to blame the computing managers (and grumbles about the President) • The computing managers try to blame the developers (and grumble about the CIO) • The developers grumble about their managers What can we do better?

27. Sobering Thoughts • Major computing projects are very complex. Inevitably there are delays and failures. • Few organizations know how to manage risk & uncertainty. • The best CIO's => Manage to minimize risk => Have the confidence of their staff who keep them truthfully informed => Have the self-confidence to keep their seniors truthfully informed

28. The End • Good processes help the development of good software: the limits of heroic efforts • Software engineering is a craft, not a fixed procedure • Minimize risk: visible process function v. time v. cost • The importance of people If the requirements are not well understood, the system will fail!