Pattern 13.3 Short-Cycle Development

Section 13.5 introduces a set of process patterns that are elaborated on throughout the case study. These patterns describe some of the broad contexts for development and a reasonable strategy for each one. Pattern 13.1, Object Development from Scratch, outlines an approach for developing a system from scratch. Pattern 13.2, Reengineering, addresses the case when an existing design is being reworked. Pattern 13.3, Short-Cycle Development, motivates development in short incremental cycles as a useful basis for many projects. 

Regardless of which route, or combination, is appropriate, most projects would benefit from carefully managed iterations (see Pattern 13.3, Short-Cycle Development) and from concurrent development work (see Pattern 13.4, Parallel Work). 

Plan the transition from as-is to to-be via intermediate steps, perhaps based on your chosen path or process. Be more specific in planning for the earlier transitions, because subsequent ones will inevitably be replanned as you approach them (see Pattern 13.3, Short-Cycle Development). 

A project development team completes a multitude of tasks over the project lifetime. Some tasks are heavily dependent on others and should be serialized, perhaps using Pattern 13.3, Short-Cycle Development others are largely independent and should proceed in parallel because downstream work is dependent on them. 

Building a prototype is an important option for many projects, and can be used as a vehicle for finding and asking the same questions. It can be built in parallel with the scenarios of this section and the system specification illustrated in the next section, and will be based on a set of classes that reflect the business model s types directly. See Section 13.3, Typical Project Evolution, on page 530, and Pattern 13.3, Short-Cycle Development (p.543), for a discussion on prototyping. 

In this pattern, you set specific short-term targets and more-general longer-term ones, and you use early feedback through scoped and managed short development cycles. This pattern is also known as one step at a time, don t chew off too much in one go, walk before you run, the spiral model, and proceed with caution. ... 

Tolerance to nicotine s effects develops rapidly and most likely involves multiple processes, although the pattern and extent of tolerance development is not identical for all of nicotine s effects. It has been proposed that rapid tolerance or desensitization occurs to the behavioral or reinforcing effects of nicotine. These effects are of such a short duration that a smoker continually cycles between a sensitized and desensitized state. This notion is consistent with the fact that drugs with high abuse liability have a rapid onset and short duration of action. 

---