Project Scheduling - Relationship between people and effort

For a small project, requirements analysis, performing design, code generation and test conduction can be done by a single person but as the size of the project increases, more people get added. Adding people later in the project often has a disruptive effect on the project causing schedules to slip even further. If more people are added to a late project, be sure that you have assigned them work that is highly compartmentalized.

The people who are added later in the project should know the system properly. In addition to the time that it takes to learn the system, it also increases the number and complexity of communication paths. Every communication path requires additional effort and time.

Project schedules are elastic. It is possible to compress or extend a desired project completion date to some extent. If delivery can be delayed, the PNR curve indicates that project costs can be reduced substantially. As the project deadline becomes tighter and tighter, you reach a point at which the work cannot be completed on schedule, regardless of the number of people doing the work. The reality should be faced and a new delivery date should be defined.

Effort should also be distributed across the software process workflow. Recommended effort distribution is referred as 40-20-40 rule. Front end analysis and design and back end testing are allocated 40% of all effort while 20% of effort is allocated to coding. The characteristics of each project must dictate the distribution of effort. Requirement analysis may comprise 10-25 percent of project effort. Effort on analysis or prototyping should increase in direct proportion with project size and complexity.