The Project Plan should be based on the SRS

Although it is reasonable to develop preliminary plans, the project plan to be used for estimating the cost of the project should be developed only after the Software Requirements Specification has been approved by the customer. Once the spec has been approved, tasks should be created in the project plan.

Each task in the project plan should have a reference back to a specific section of the SRS. If you do this, then it is easy to handle questions about each task as you quote the time required for the implementation.

So what is the best way to do that?

I’ve tried putting paragraph numbers from the SRS into the project plan as references. Unfortunately that only works until you first modify the SRS.

Instead I recommend giving each requirement in the SRS a unique name and then using those names in the project plan. For example, a section of the SRS may say “Aging Report” and the project plan will have a task titled “Aging Report”. It is easier to avoid changing the names of sections in the SRS than it is to avoid changing section numbers.

Ideally some software would allow the SRS and the project plan to be linked together. I haven’t seen any software yet that allows us to do that.