Fourteen tips
to better your PSPSM [1]
Tip #3
Daniel M. Roy
(President STPP, Inc.
SEI visiting scientist and
transition partner)
Abstract: Fourteen tips are proposed to better use the PSP framework so that
improvement is made easier and PSP is routinely used on the job. Tips for PSP
support tools and about expanding the PSP to small teams are added to make the
transition to Team Software Process (TSPSM[2]) even smoother.
3. Better your PIP
The Process Improvement Proposal (PIP) form typically puzzles the student. What does the instructor expect you to do with it? Simple: you are expected to think at level 5!
Anything goes in a PIP from your gripes and questions to your most brilliant insight. If you’re wondering what you can say in a PIP, here is a sample:
· Estimates:
ü Review your size estimation template. Document your assumptions in the PIP. When you’re done with the assignment, revisit the PIP and the actuals in the size estimation template. Did you forget objects? Did you guess the right number of methods? Did you select the right relative size? What can you do at conceptual design time to do better next time?
ü Compare time estimates vs. actuals by phase. If you spend more time in planning design, DLDR, CR, chances are you spent less than planned in code, compile and test. These are clear signs of an improving process.
· Defects:
ü Distribution of defects (plan vs. actual) with PSP2 that tells you a lot. At DLDR, should you be in ambush for those pesky 3 defects you expected to inject in design? These predictions turn out remarkably accurate more often than not. Write it down in the PIP; someone’s got to remember!
ü You reviewed your code at 500 LOC/h. You were expecting to catch 6 defects but got only 3. What are you gonna do about that? Tell me in your PIP.
ü You reviewed you plan and noticed your A/FR was 0.8. You went back to your DLDR, CR estimates and boosted them to get an A/FR of 3. Make a note in the PIP. When you’re done with the assignment, have a look at the actuals: Is test time down? Is test defect density lower than planned? Remember the lesson.
· Plan summary:
ü If you could not build with reuse (%reuse) are you at least building for reuse (%new reuse)? What can you do about that at design time?
ü Discuss statistical validity of data. One error in a 20 LOC program means a whopping 50/KLOC. Or, your yield just crashed to 33%. But that’s because you had 3 defects in a 320 LOC monster and you misspelled the same identifier twice. See? It’s not that big a deal after all. But update your checklist and keep being vigilant.
· General:
ü Questions, gripes, next goals (preferably quantitative)?
ü What worked well for you? What did not? (this may be more important than what did work if you can find out why).
ü Think about what you can do with this process element, data or insight on the job.
ü Any surprise? Any flash of insight? Write it down RIGHT NOW. Watts never said you have to wait until post mortem. By then, you will have forgotten.
And that’s just a sample. Your data, if you look at it, will whisper many more issues in your ear.
I systematically reject any PSP exercise package that does not contain a valid PIP. After all, PSP is a level 5 process for individuals. Can you imagine a level 5 process without process improvement?
To foster this level 5 mode of thinking, I also request that students keep submitting the whole stack of PIPs (old as well as new) with every assignment. This typically consists of only 3 or 4 pages and has the advantage of making the tracking of improvement action easier.
Furthermore, the form can easily be modified to handle the recording of the dates at which the PIPs were open and closed. Figure 3-1 shows this principle at work with a slightly modified PIP form.
Figure 3-1: Tracking PIPs
Finally, to even better emphasize the all-important continuous improvement aspect of PSP, I propose the following additions to the standard PIP:
· Dates at which each entry is made
· Remarks, notes and lessons learned (success as well as failure)
· Next goals (prioritize the PIPs)
· Questions (to yourself, the instructor, the SEPG or the local expert).
Figure 3-2 shows an example of these additions to the standard PIP at work.
Figure 3-2: PIP additions
Continuously tracking improvement during the PSP training as well as on the job is easier and can be done more consistently with these simple additions.