Never calculate without first knowing the answer - John Archibald Wheeler
When we work using other peoples money, we have an obligation to know what the all in cost is, or when we plan to be done, and if we have confidence that the technical outcome will be acceptable to those who hve paid for the outcomes of our project.
In order to answer these questions, we need to make estimates for cost, schedule, and technical performance before the project is complete, long before it is complete. These estimates are probabilistic forecasts of future outcomes based on past performance or out best assessment of what could be the outcomes.
We owe it to those providing the money for our. No business can operate for long without knowing what it's future obligations are for cash flow and payments to staff and vendors. To ignore this fundamental aspect of business is to ignore the creation of value for those providing the funding for that creation.
The ability to credibly estimate is a core competency of all engineeting and product development activities.
