I'm looking for a reference to the following. I commonly hear that one-third of a projects time will be spent in design, one-third in implementation, and one-third in testing. The three phases of development seems to be derived from the waterfall model. But, where did the time division originate (1/3, 1/3, 1/3)? Is there a paper or book that this is from?
The rule of thumb you're describing sounds extremely similar to Brooks' rule of thumb, as presented in the Mythical Man-Month:
For some years I have been successfully using the following rule of thumb for scheduling a software task:
1/4 component test and early system test
1/4 system test, all components in hand.
This differs from conventional scheduling in several important ways:
- The fraction devoted to planning is larger than normal. Even so, it is barely enough to produce a detailed and solid specification, and not enough to include research or exploration of totally new techniques.
- The half of the schedule devoted to debugging of completed code is much larger than normal.
- The part that is easy to estimate, i.e., coding, is given only one-sixth of the schedule.
I don't know where exactly your rule of thumb comes from, but it certainly looks like a derivative of Brooks' rule of thumb.