1. Iterative Rework: The Good, the Bad, and the Ugly
Richard E. Fairley and Mary Jane Willshire, “Iterative Rework: The Good, the Bad and the Ugly”, Computer Cover Feature, Sept. 2005, pp
SE 516 Technical Article Presentation
Yvonne Krashkevich

2. Iterative Rework: The Good, the Bad, and the Ugly
Abstract
As the famous Greek philosopher, Heraclitus proclaimed “The only thing that is constant is change”, so too is it common to find change in today’s software development projects.  Varying degrees of change can adversely impact project delivery, budget and quality.  Given this state of flux, rework is both inevitable and beneficial, however, knowing how to balance too much verses too little is the key to a project’s success or failure. This article focuses on the nature of rework and why it occurs.  The article also reviews a process for collecting rework data to determine associated root causes, identify rework trends and to isolate avoidable rework.  Identifying and correcting the root causes of avoidable rework improves productivity, quality, profits and ultimately customer satisfaction.

3. Iterative Rework: The Good, the Bad, and the Ugly
Iterative Development Models
Continuously integrate and validate the evolving product
Frequently demonstrate progress
Alert developers early on about problems
Deliver subset capabilities early on
Systematically incorporate the inevitable rework that occurs in software development

4. Iterative Rework: The Good, the Bad, and the Ugly
Agile Development
Five principles of Agile process models
Continuously involve the customer
Develop test cases/scenarios before releasing the next version
Implement and test the next version
Periodically deliver subsets of the product

5. Iterative Rework: The Good, the Bad, and the Ugly
Agile Development cont.
Steps in the Agile Development Process
Hear customer story
Specify Requirements
Add new features; review, test and rework
Demonstrate capabilities
Iterations occur in cycles of one day or less
Note: “Requirements and Architecture Evolve”

6. Iterative Rework: The Good, the Bad, and the Ugly
Incremental Build
Based on stable requirements and architecture
Partitions the design into prioritized build sequences
Each build adds capabilities to the incrementally growing product
Build-validate-demonstrate iterations
Versions can overlap
Customer is usually not in the loop

7. Iterative Rework: The Good, the Bad, and the Ugly
Premise of Iterative Development - Rework is inevitable
It provides the ability to gracefully modify the current version of an evolving product while adding capability to produce the next version
It avoids the well known pitfalls of massive integration, testing and rework encountering in the waterfall model.

8. Iterative Rework: The Good, the Bad, and the Ugly
Four Dimensions Characterize Software

9. Iterative Rework: The Good, the Bad, and the Ugly
Types of Rework
Evolutionary
Modifies one or more of the current version’s four dimensions to provide new capabilities in the next version
Due to change in requirements that developers were not aware of when developing the current version.
Avoidable
Work that no one would have to do had the previous work been correct, complete and consistent (i.e. satisfied it’s requirements)

10. Iterative Rework: The Good, the Bad, and the Ugly
Rework Taxonomy

11. Iterative Rework: The Good, the Bad, and the Ugly
Distinguishing Between Good and Bad
The fuzzy part is interpretation
Customers say that they are only clarifying requirements the developers should have understood (i.e. retrospective)
The developers maintain that the customers changed the requirements (i.e. evolutionary)

12. Iterative Rework: The Good, the Bad, and the Ugly
Collecting and Analyzing Rework Data
The goal is to identify major trends and determine the rework’s root causes
Four common techniques
Anecdotes
Observation
Record keeping
Automation

13. Iterative Rework: The Good, the Bad, and the Ugly
How Much is Acceptable?
Rule of thumb – rework is acceptable at % of the total effort
More than 20% of the total effort indicates problems in the work process
Less than 10% indicates insufficient reviewing, revising and testing

14. Iterative Rework: The Good, the Bad, and the Ugly
Dealing with the Ugly – How Control Charts Work
Excessive
Insufficient

15. Iterative Rework: The Good, the Bad, and the Ugly
Rework can amount to 80% of all work
Effort is saved by reducing defect, this reducing avoidable rework

16. Iterative Rework: The Good, the Bad, and the Ugly
Six key questions to Process Improvement

17. Iterative Rework: The Good, the Bad, and the Ugly
Conclusion
Identifying and correcting the root causes of avoidable rework improves productivity, quality, profits and ultimately customer satisfaction.

18. Iterative Rework: The Good, the Bad, and the Ugly
Questions???