Symptom: Requirements are clear, but contracts are not explicit.
An accurate cost estimate is based on clear, mutually understood deliverables. Said another way, every project is based on a clear contract that specifies deliverables and price. Then, if requirements change, the organization should renegotiate the contract (especially the time and price).
If the organization does not negotiate clear agreements (contacts) with its clients before starting a project, then there will be no baseline on which to build any needed changes. This makes it difficult to estimate the incremental cost of mid-project changes.
Another (more generic) way to state the problem is as follows:
