Software Engineering

4.6 
Project and technical planning
The execution of the software development project is guided by a set of project and 
technical plans. However, it is the planning exercise and decisions that are central 
to the success of the project. The plans themselves only document the approach 
or course of action designed to achieve immediate or short-term objectives. Initial 
plans established for the software development project will need to be revised as 
the software requirements and architecture are ascertained and characterized. It is 
not possible to establish a comprehensive plan addressing the entire software devel-
opment effort during the early stages of development. Therefore, it is necessary for 
project and technical plans to be revised prior to each review or milestone to reflect 
the understanding obtained during the preceding phase of development. 
Figure 4.9
 
shows the evolution of the software architecture throughout the first three develop-
ment phases and how this leads to improving project and technical plans.
At the start of the software development effort project plans should simply 
establish the major milestones to be achieved and the technical activities, documen-
tation, and models that will be generated to define the software requirement. Prior 
to the software requirements review, project and technical plans should be extended 
to address the technical activities that will be conducted to delineate the product 
functional and physical architectures. These technical plans are summarized in 
the IMP and arranged as a time-based IMS. The IMS is a networked, multilayered 
schedule showing the significant tasks required to establish the software product 
architecture. These project and technical plans should be the fundamental elements 
reviewed at the software requirements review (SRR). Successful completion of the 
SRR would authorize the work articulated by these planning devices. Throughout 
the software development effort, these plans should be revised to align the technical 
work with the effort remaining to complete the project objectives.