Which is MOST APPROPRIATE when estimating costs where the scope is uncertain?

When the scope of a project or program is uncertain, the most appropriate and pragmatic approach is to use progressive elaboration. This involves creating an initial, high-level estimate, often called a Rough Order of Magnitude (ROM) estimate, based on the best available information. This initial estimate is understood to have a wide accuracy range. As the project progresses through its lifecycle and more details about the scope become defined and clarified, the cost estimate is iteratively refined. This approach allows for initial planning and decision-making while formally acknowledging and managing the inherent uncertainty.

A. Waiting for complete certainty is often impractical, as it can lead to "analysis paralysis" and prevent timely decision-making and project initiation.
B. Estimating only certain areas provides an incomplete and misleadingly low cost, which constitutes poor financial planning and risk management.
D. This describes a "design to cost" strategy, which is about controlling scope to fit a budget, not a method for estimating the cost of an uncertain scope.

1. AXELOS. (2010). Management of Value (MoV®). The Stationery Office.

Section 3.4.2, 'Estimate and evaluate': This section within the MoV study plan states, "The level of detail and accuracy of the estimates will depend on the nature of the subject and the information available." This directly supports the principle that estimates are made with current information and are subject to refinement as more information becomes available (as described in option C).

2. AXELOS. (2010). Management of Value (MoV®). The Stationery Office.

Section 4.3, 'The MoV study plan': The entire structure of an MoV study, moving from an 'Information phase' to an 'Evaluation phase,' is designed to reduce uncertainty. Initial assumptions and estimates made at the start are tested and refined as detailed information is gathered, aligning perfectly with the iterative estimation approach.

3. University of Washington. (n.d.). Project Management Courseware, PMGT 510.

Module on Project Cost Management: University-level project management courses, often based on globally recognized standards, teach the concept of "Progressive Elaboration." This is defined as the iterative process of increasing the level of detail in a plan as more information becomes available. This principle is directly applied to cost estimation, where initial rough estimates are refined into more detailed and accurate ones as the project scope is clarified. This academic principle underpins the logic in option C.