問37
頻出度★★★
Aさんは新規プロジェクトの計画段階の作業をしており，開発コストの見積りに着手した。この段階で短期的に概算費用を見積もる方法として，最も適切なものはどれか。
令和8年度 ITパスポート試験 問37
マネジメント系システム開発技術 › システム開発技術
This question's explanation and your answers so far.
解説
問 37
Incorrectア
The Function Point method (FP method) determines scale by counting the number and complexity of software functions such as inputs, outputs, and files, and then estimates effort and cost from that. It requires the functional specifications to be reasonably clear, and the work of counting functions is itself time-consuming, so it is not suited for making a rough estimate in a short time in the early planning phase when requirements are not yet fixed.
Incorrectイ
The method of estimating the cost of each work unit and summing them is called bottom-up estimation. It requires the work to be broken down into fine units with a WBS, and estimating each task and adding them up takes time. Its accuracy is high, but it is a technique performed after the details of the work are fixed, so it is not suited for a short-time rough estimate in the planning phase.
Incorrectウ
The method of estimating based on the expected number of lines of code (LOC), such as the program-step method, is used at a stage where the design has progressed enough to predict the code size. In the early planning phase the number of lines itself cannot be predicted accurately, so it is not suitable for an early rough estimate in a short time.
- エ
正解 The correct answer is エ, “Estimate by referring to similar projects.” This is a technique called analogy-based estimation, which makes a rough estimate based on the actual data (scale, effort, cost, etc.) of similar projects carried out in the past, adjusting for the differences from the current project. In the planning phase the details of the requirements and design are not yet fixed, but because analogy-based estimation only needs to refer to past results, it can produce a rough cost estimate in a short time even at an early stage when detailed information is scarce. It best fits the situation asked about, “making a rough cost estimate in the short term during the planning phase.”
ここがポイント
- Analogy-based estimation makes a rough estimate based on the actual results of similar past projects. It can produce a rough estimate in a short time even in the early planning phase when detailed information is scarce, making it suitable for early rough cost estimation.
- Understand how to use the different estimation techniques: the FP method, LOC method, and bottom-up estimation all require detailed information and emphasize accuracy, suiting later phases, whereas analogy-based estimation suits early stages with little information.
用語