The purpose of this workflow detail is to develop the components and enclosures of the Software Development Plan, and then have them formally reviewed, for feasibility and acceptability to stakeholders, and as the basis for the fine-grained plan for the next iteration (the Iteration Plan). The major effort in creating these artifacts comes early in the inception phase; thereafter, when this workflow detail is invoked at the beginning of each iteration, it is to revise the Software Development Plan (and its enclosures) on the basis of the previous iteration's experience and the Iteration Plan for the next.
This workflow detail will obviously stress the Project Manager's estimation, planning and writing skills. Also, the Project Manager must ensure buy-in from affected stakeholders during the construction of these plans, so presentation and communication skills will also be important. The Project Reviewer will need to be experienced in the estimation of projects in the relevant business or technical domain and should be able to make judgments about the validity of assumptions made by the Project Manager.
Estimation should ideally be based in the organization's own experience, which is then used to calibrate an estimation model, such as COCOMO. (See [BOE81] for a description of the original model) If the Project Manager is starting from scratch, using default values for model coefficients, it will be important to use other methods to validate the estimates. Just as important is to obtain staff and other stakeholder agreement that the estimates are realistic and achievable. However, the Project Manager has to take into account the experience of staff giving feedback about estimates. More junior staff may be just guessing numbers and then adding large margins for error; conversely, their effort estimates may be naively low. The Project Manager must be circumspect when dealing with estimates from junior staff, and be prepared to counsel them when necessary, and offer the assistance of a more experienced peer. See Activity: Plan Phases and Iterations for more information about estimation.
All enclosed plans and sections of the Software Development Plan should be evaluated through internal walkthroughs and reviews before the Project Planning Review occurs.