The Project Life Cycle
　　項(xiàng)目生命期
　　Project managers or the organization can divide projects into phases to provide better management control with appropriate links to the ongoing operations of the performing organization. Collectively, these phases are known as the project life cycle. Many organizations identify a specific set of life cycles for use on all of their projects.
　　項(xiàng)目經(jīng)理或組織可以把每一個(gè)項(xiàng)目劃分成若干個(gè)階段，以便有效地進(jìn)行管理控制，并與實(shí)施該項(xiàng)目組織的日常運(yùn)作聯(lián)系起來(lái)。這些項(xiàng)目階段合在一起稱為項(xiàng)目生命期。許多組織識(shí)別出一套具體的生命期供其所有的項(xiàng)目使用。
　　Characteristics of the Project Life Cycle
　　項(xiàng)目生命期的特征
　　The project life cycle defines the phases that connect the beginning of a project to its end. For example, when an organization identifies an opportunity to which it would like to respond, it will often authorize a feasibility study to decide whether it should undertake the project. The project life cycle definition can help the project manager clarify whether to treat the feasibility study as the first project phase or as a separate, stand-alone project. Where the outcome of such a preliminary effort is not clearly identifiable, it is best to treat such efforts as a separate project.
　　項(xiàng)目生命期確定了將項(xiàng)目的開(kāi)始和結(jié)束連接起來(lái)的階段。例如，當(dāng)某個(gè)組織發(fā)現(xiàn)一個(gè)可以考慮和利用的機(jī)會(huì)時(shí)，它通常會(huì)責(zé)成有關(guān)人員進(jìn)行可行性研究，以決定該項(xiàng)目是否值得立項(xiàng)。項(xiàng)目生命期的定義有助于項(xiàng)目經(jīng)理弄清是否應(yīng)將該項(xiàng)可行性研究視為項(xiàng)目的第一個(gè)階段，或者將其當(dāng)做一個(gè)單獨(dú)的項(xiàng)目。當(dāng)這種初步努力的結(jié)果無(wú)法識(shí)別清楚時(shí)，最好將其當(dāng)做單獨(dú)的項(xiàng)目進(jìn)行處理。
　　The transition from one phase to another within a project's life cycle generally involves, and is usually defined by, some form of technical transfer or handoff. Deliverables from one phase are usually reviewed for completeness and accuracy and approved before work starts on the next phase. However, it is not uncommon for a phase to begin prior to the approval of the previous phase's deliverables, when the risks involved are deemed acceptable. This practice of overlapping phases, normally done in sequence, is an example of the application of the schedule compression technique called fast tracking.
　　從項(xiàng)目生命期的一個(gè)階段轉(zhuǎn)到另一階段通常是某種形式的技術(shù)交接，這種階段轉(zhuǎn)移通常也由這種技術(shù)交接確定。前一階段產(chǎn)生的可交付成果通常要接受是否已經(jīng)完成和準(zhǔn)確的審查，在驗(yàn)收之后才能開(kāi)始下一階段的工作。但是，如果認(rèn)為所涉及的風(fēng)險(xiǎn)是可以接受的話，后一階段可以在前一階段可交付成果通過(guò)驗(yàn)收之前開(kāi)始。通常這種將按照先后順序完成的兩個(gè)階段重疊的做法，是應(yīng)用所謂快速跟進(jìn)進(jìn)度壓縮技術(shù)的一個(gè)例子。
　　There is no single best way to define an ideal project life cycle. Some organizations have established policies that standardize all projects with a single life cycle, while others allow the project management team to choose the most appropriate life cycle for the team's project. Further, industry common practices will often lead to the use of a preferred life cycle within that industry.
　　目前沒(méi)有確定項(xiàng)目生命期的惟一最好辦法。某些組織的既定方針是用一個(gè)項(xiàng)目生命期作為標(biāo)準(zhǔn)的方式處理所有的項(xiàng)目，而另外一些單位則允許項(xiàng)目管理團(tuán)隊(duì)為其項(xiàng)目選擇最適合的項(xiàng)目生命期。另外，行業(yè)的通用做法經(jīng)常造成本行業(yè)內(nèi)部使用某種約定俗成的項(xiàng)目生命期。項(xiàng)目生命期的定義還將確定項(xiàng)目開(kāi)始與結(jié)束時(shí)的哪些過(guò)渡行動(dòng)應(yīng)包括在項(xiàng)目范圍之內(nèi)，哪些則不應(yīng)包括在內(nèi)。這樣，就可以用項(xiàng)目生命期的定義把項(xiàng)目和項(xiàng)目實(shí)施組織持續(xù)的日常運(yùn)作業(yè)務(wù)聯(lián)系在一起。
　　Project life cycles generally define:
　　項(xiàng)目生命期通常規(guī)定：
　　What technical work to do in each phase （for example, in which phase should the architect's work be performed?）
　　項(xiàng)目的各個(gè)階段應(yīng)當(dāng)從事何種技術(shù)工作（例如，建筑師的工作應(yīng)放在項(xiàng)目的哪個(gè)階段完成）。
　　When the deliverables are to be generated in each phase and how each deliverable is reviewed, verified, and validated
　　項(xiàng)目各階段可交付成果應(yīng)何時(shí)生成，以及如何審查、核實(shí)和確認(rèn)。
　　Who is involved in each phase （for example, concurrent engineering requires that the implementers be involved with requirements and design）
　　項(xiàng)目各階段由哪些人員參與（例如，并行工程要求實(shí)施人員參與制定要求說(shuō)明書(shū)和設(shè)計(jì)）。
　　How to control and approve each phase.
　　如何控制和批準(zhǔn)項(xiàng)目各個(gè)階段。
　　Project life cycle descriptions can be very general or very detailed. Highly detailed descriptions of life cycles can include forms, charts, and checklists to provide structure and control.
　　說(shuō)明項(xiàng)目生命期時(shí)可以十分籠統(tǒng)，也可以非常詳細(xì)。非常詳細(xì)的說(shuō)明可以包括許多表格、圖表和核對(duì)表，使其條理清楚，便于控制。
　　Most project life cycles share a number of common characteristics:
　　大多數(shù)項(xiàng)目生命期的說(shuō)明具有若干共同特點(diǎn)：
　　Phases are generally sequential and are usually defined by some form of technical information transfer or technical component handoff.
　　項(xiàng)目階段一般按順序首尾銜接，通常根據(jù)某種形式的技術(shù)信息傳遞或技術(shù)部件交接來(lái)確定。
　　Cost and staffing levels are low at the start, peak during the intermediate phases, and drop rapidly as the project draws to a conclusion. Figure 2-1 illustrates this pattern.
　　人力投入和費(fèi)用，開(kāi)始時(shí)低，隨之增高，在項(xiàng)目接近收尾時(shí)迅速下降。這種模式如圖2-1所示。


　　Figure 2-2. Stakeholders' Influence Over Time

　　圖2-2利害關(guān)系者影響隨著時(shí)間的變化

　　The level of uncertainty is highest and, hence, risk of failing to achieve the objectives is greatest at the start of the project. The certainty of completion generally gets progressively better as the project continues.
　　項(xiàng)目開(kāi)始時(shí)，成功地完成項(xiàng)目的可能性最低，因此風(fēng)險(xiǎn)和不確定性最高。隨著項(xiàng)目繼續(xù)績(jī)效，成功地完成項(xiàng)目的可能性通常都逐漸上升。
　　The ability of the stakeholders to influence the final characteristics of the project's product and the final cost of the project is highest at the start, and gets progressively lower as the project continues. Figure 2-2 illustrates this. A major contributor to this phenomenon is that the cost of changes and correcting errors generally increases as the project continues.
　　項(xiàng)目開(kāi)始時(shí)，項(xiàng)目利害關(guān)系者對(duì)項(xiàng)目產(chǎn)品最后特點(diǎn)和項(xiàng)目最后成本的影響力最強(qiáng)，而隨著項(xiàng)目的績(jī)效，這種影響逐步減弱。圖2-2形象地說(shuō)明了這一點(diǎn)。造成這種現(xiàn)象的主要原因是隨著項(xiàng)目的績(jī)效，變更計(jì)劃和糾正失誤的代價(jià)通常與日俱增?！　?


　　Figure 2-2. Stakeholders' Influence Over Time

　　圖2-2利害關(guān)系者影響隨著時(shí)間的變化

　　Although many project life cycles have similar phase names with similar deliverables, few life cycles are identical. Some can have four or five phases, but others may have nine or more. Single application areas are known to have significant variations. One organization's software development life cycle can have a single design phase, while another can have separate phases for architectural and detailed design. Subprojects can also have distinct project life cycles. For example, an architectural firm hired to design a new office building is first involved in the owner's definition phase while doing the design, and in the owner's implementation phase while supporting the construction effort. The architect's design project, however, will have its own series of phases from conceptual development, through definition and implementation, to closure. The architect can even treat designing the facility and supporting the construction as separate projects, each with its own set of phases.
　　盡管許多項(xiàng)目生命期具有彼此相似的階段名稱，所要求的可交付成果名稱也極其相似，但其內(nèi)容絕少雷同。某些項(xiàng)目有4個(gè)或5個(gè)階段，但另一些項(xiàng)目可多達(dá)9個(gè)階段以上。即使在某單一應(yīng)用領(lǐng)域內(nèi)，也會(huì)有很大差別，如一個(gè)組織的軟件開(kāi)發(fā)生命期可能只有一個(gè)設(shè)計(jì)階段，而另一個(gè)組織卻可能將其分為功能設(shè)計(jì)和詳細(xì)設(shè)計(jì)兩個(gè)單獨(dú)的階段。項(xiàng)目?jī)?nèi)的子項(xiàng)目也可以有明顯的項(xiàng)目生命期。例如，一家建筑師事務(wù)所受雇為他人設(shè)計(jì)新辦公樓時(shí)，首先在設(shè)計(jì)時(shí)參與了業(yè)主的設(shè)計(jì)要求制定階段，隨后又在協(xié)助施工時(shí)參與了業(yè)主的實(shí)施階段，協(xié)助施工。但建筑師本身的設(shè)計(jì)項(xiàng)目也有自己的一系列階段，包括項(xiàng)目構(gòu)思、要求制定、實(shí)施，直至項(xiàng)目收尾。這位建筑師甚至可以把辦公樓的設(shè)計(jì)和對(duì)施工的協(xié)助視為兩個(gè)不同的項(xiàng)目，分別包括各自的明顯階段。