CEN 4021 Software Engineering II

1. CEN 4021 Software Engineering II Change Control Instructor: Masoud Sadjadi http://www.cs.fiu.edu/~sadjadi/ sadjadi@cs.fiu.edu

2. Acknowledgements • Dr. Onyeka Ezenwoye • Dr. Peter Clarke

3. Agenda • Change Control

4. Change control • Software projects are prone to changes • There is a general belief that software can be easily modified • Changes must be implemented with care • The worst situation occurs when changes are allowed without proper control

5. Change control • Definition • A set of information and the sequence of activities used in the tracking and managing of a change request from its inception to its close.

6. Changes control • The processes, methodologies and tools needed to manage change requests must be designed aheadoftime. • The process and people resources needed as part of the management of change request should be set aside, trained and include in the budget and plan.

7. Example change request process • Every change to product or process should start with a baseline which represents the first formally version. • Then go through a change control process • Change requests may come from anywhere but need to be formalized so it can be tracked back to its source.

8. Example change request process • Formalization can be achieved with the use of a change request form. • Which should include: • Requestor’s name • Date of the request • Request description • Reason for the request • Priority of the request • Preferred date of completion • Funding source for the request • Areas known to be affected by the change

9. Example change request process • Once the request form is filed out, it should be submitted to a someone who formally takes charge of the request. • Upon submission, change request needs to be reviewed. • Implications to other parts of the project needs to be assessed

10. Example change request process • Possible items for change impact analysis include: • Schedule • Cost • Human resources • Processes and tools • Product content and size • Product marketing strategy

11. Example change request process • Change control process also needs to take into account how a change request affects the customers’ work flow or environment • Change requests to software must be defined, documented and disseminated.

12. Example change request process Request denied Accept (A) Accept ? Change Request Review of change impact Store all related material Accept (B) product Schedule for follow-on release Process and tools Make appropriate plan changes personnel schedule Complete the changes cost Close change request

13. Change impact analysis • Software impact analysis identifies the effects of a software change request. • Each impact needs to be quantified and prioritized. • Measurement scheme must be designed such that each change request may be gauged in relation to other change requests.

14. Change impact analysis • Example of quantifying some of the impacted areas follow • Schedule impact may be designated with values ranging from 1 to 4 (days, weeks, months) • Personnel impact may also be designated with values ranging from 1 to 4 • Cost impact may be quantified using the schedule and personnel impact, converted to dollars

15. Change impact analysis • Measurement metrics may depend on the type of project • After impacted areas are quantified, change requests can be compared by area and possibly ordered • Each impacted area may be assigned a numerical weight and prioritized • Actual cut-off criteria would depend on many parameters like history, experience, etc

16. Cumulative effects of changes • A small change in artifact can hugely affect both end product and the work effort required to develop the product. • A small change in a database field might generate the following changes: • Design and code changes to all areas that utilize that field • Modifications to help scripts and user documentation • Reviews of all changes

17. Cumulative effects of changes • A small change in a database field might generate the following changes: • Development of new test scripts and scenarios • Running of new test scripts and re-running of older ones. • Fixes for any related problems from the tests • Updates to the library and change control tools • Locking and promoting of the successfully changes materials • Communication of the completed change to all interested parties

18. Cumulative effects of changes • Complications from the ripple effect of related work that can dramatically affect schedule and cost • A change request may lead to one line of altered code but result in one week of effort to complete that change request. • Team managing the change process must have good knowledge of the product and all items associated with it.

19. Cumulative effects of changes • Most projects are not well equipped to handle the extra workload required to assess change requests • It takes a very disciplined project management team to insist on proper change management • Change request may psychologically effect the team