Software Development & Software Engineering is a little like following a recipe to cook.
Just as recipes attain perfection over generations, the process of estimation evolves gradually and takes a couple of cycles/years to mature.
Estimation Level & Unit(s)
- amount of detail needed across the various phases of the software development life-cycle is different
- estimation at various levels is done based on the understanding and expertise of the concept, skills and other parameters involved in the building and delivery process
- effort needed (Estimate) and duration to get the software built (Duration) are two different aspects
- unit of estimation (Days/Hours) must not be mis-interpreted
- sum total of All Tasks across All Requirements has to add up to the estimate of the Total Concept