CAPM Practice: Explain when it is appropriate to use a predictive, plan-based approach

A fixed-price contract with defined acceptance criteria requires that requirements be sufficiently complete and stable before work begins. The fixed price is based on a defined scope; if scope is unclear, the price cannot be fixed. This contractual structure inherently favors predictive methodology where scope is locked before execution.

**Why not A:** Discovering requirements iteratively while maintaining a fixed cost contradicts fixed-price contract fundamentals. If requirements evolve, the scope changes, making a fixed price untenable. Fixed-price contracts require scope clarity upfront to establish a fair and defensible price.

**Why not B:** Negotiating requirements during execution undermines the fixed-price structure. The price was set based on a specific scope; negotiating requirements mid-project would create scope uncertainty that conflicts with the fixed-price agreement and defined acceptance criteria.

**Why not D:** Having the contractor define requirements based on industry standards removes the buyer's control over what they are paying for. In a fixed-price contract, the buyer specifies requirements and the contractor prices and delivers against them. The buyer, not the contractor, owns the requirements.