The Art of Project Management

2.6. Summary

• Schedules serve three functions: allowing for commitments to be made, encouraging everyone to see her work as a contribution to a whole, and enabling the tracking of progress. Even when schedules slip, they still have value.

• Big schedules should be divided into small schedules to minimize risks and increase the frequency of adjustments.

• All estimates are probabilities. Because schedules are a collection of estimates, they are also probabilities. This works against schedule accuracy because probabilities accumulate (80% × 80% = 64%).

• The earlier that estimates are made, the less accurate they are. However, rough estimates are the only way to provide a starting point for better ones.

• Schedules should be made with skepticism, not optimism. Invest in design to shed light on assumptions and generate reliable confidence.