Final answer:
Bottom-up estimates are normally developed during the Planning phase of a project, which allows for detailed and accurate estimations based on the selected design choices and the project's comprehensive scope.
Step-by-step explanation:
Based on the project expertise and effort required to develop bottom-up estimates, they are normally developed during the c. Planning phase of a project. Bottom-up estimating is a detailed and accurate method of project estimation which typically involves estimating individual tasks and then rolling them up to determine the overall project estimate. This technique is time-consuming and requires a deep understanding of the project's scope and specifics. Therefore, it is best suited for the Planning phase, where detailed information is available, and precise estimates can contribute significantly to the project's success.
During the Planning phase, details from initial research are brought together and design choices are made, which allows the team to move forward to implementation. The creation of detailed designs from a concept is essential, as it can influence the outcome of the project. These are refined as the project progresses, ensuring flexibility and accommodating changes that are integral during the realization phase of the project. Consequently, the Planning stage is the ideal time for developing bottom-up estimates.