結局、プロジェクトのコストに関係したビジネス満足というあいまいな感覚なのである。 Rather than saying that a project is failed because it is late, or has cost overruns - I would argue that it's the estimate that failed. So the CHAOS report isn't chronicling software project failure, it's chronicling software estimation failure. So what counts as success? If we could measure it the answer has to be Return on Investment. Sadly this is usually next to impossible to measure (see my discussion in CannotMeasureProductivity) In the end it's a fuzzy sense of business satisfaction relative to the cost of the project. 引用: WhatIsFailure(失敗とは): マーティンファウラー
For me, estimation is valuable when it helps you make a significant decision. My first example of an estimation-informed decision is allocation of resources. Organizations have a mostly fixed amount of money and people, and usually there are too many worthwhile things to do. So people are faced with decisions: do we do A or B? Faced with such a decision it's useful to know how much effort (and cost) each will involve. To make sensible decisions about what to do, you need to have a feel for both the cost and the benefits. 引用: PurposeOfEstimation(見積もりの目的): マーティンファウラー
they usually feel most productive when they make progress on tasks and when they have only a few context switches and interruptions. However, observing developers’ workdays revealed that they constantly switch contexts, often multiple times an hour. For example, developers switched tasks on average 13 times an hour and spent just about 6 minutes on a task before switching to another one. “ “開発者たちは、タスクの進捗を感じる時や、コンテキストの切り替えや中断が少ない時に最も生産的だ と感じることが多いと報告しています。 しかし、開発者の労働日を観察すると彼らは絶えずコンテキストを切り替えており、しばしば1時間に何 度もこれを行っています。例えば、開発者は平均して1時間に13回タスクを切り替え、約6分間タスクに 集中して別のタスクに移っています” 引用 : Rethinking Productivity in Software Engineering Chapter Developers’ Diverging Perceptions of Productivity
perceptions of productivity over the course of a workday” “湾曲した回帰線は、個々の開発者が信頼範囲を示す影付きの領域で生産的だと感じた日の全体的な パターンを示しています。朝の人々はまれで(20%)、最大のグループは午後の人々(40%) これらの結果は、開発者が多様な生産性パターンを持っている一方で、 個人が毎日自分の習慣的なパターンに従っているように見えることを示唆しています。” 引用 : Rethinking Productivity in Software Engineering Chapter Developers’ Diverging Perceptions of Productivity