📚 Worksheet Answers – Chapter 20: Project Management | 第20章练习答案：项目管理
This worksheet answer guide covers Chapter 20: Project Management for Cambridge A-Level Business. It provides model answers to common worksheet questions on critical path analysis, Gantt charts, just-in-time, lean production, Kaizen, quality circles, and project management software. Use the answers to check your own work and to improve exam technique.
本练习答案指南涵盖剑桥A-Level商务第20章：项目管理。它提供关键路径分析、甘特图、准时制、精益生产、持续改善、质量圈和项目管理软件等常见练习题的示范答案。你可以用这些答案核对作业并提高考试技巧。
1. Key Terms Review | 关键术语复习
Q1. Define ‘project management’. | 定义“项目管理”。
Project management is the planning, organising, leading and controlling of resources to complete a specific project within defined time, cost and quality limits. It differs from routine operations because each project is unique and has a clear start and finish.
项目管理是指对资源进行计划、组织、领导和控制，在规定的工期、成本和质量范围内完成特定项目。它不同于日常运营，因为每个项目都是独特的，并且有明确的起止时间。
Q2. State three stages of project management. | 说明项目管理的三个阶段。
- Initiation and planning: defining objectives, scope, budget and schedule. | 启动与规划：确定目标、范围、预算和时间表。
- Execution and monitoring: allocating resources, carrying out tasks and tracking progress. | 执行与监控：分配资源、开展任务并跟踪进度。
- Closing and review: delivering the outcome and evaluating performance against objectives. | 收尾与评估：交付成果并根据目标评价表现。
Q3. Distinguish between a project and routine operations. | 区分项目与日常运营。
A project is a one-off activity with a specific objective, fixed timescale, and a defined end point. Routine operations are continuous, repeatable activities carried out regularly to maintain business functions. A project team may be temporary, whereas operations staff are usually permanent.
项目是具有特定目标、固定时间表和明确终点的一次性活动。日常运营是为维持企业职能而定期开展的持续性、可重复活动。项目团队可能是临时的，而运营人员通常是长期的。
2. Critical Path Analysis – The Basics | 关键路径分析基础
Q4. What is critical path analysis (CPA)? | 什么是关键路径分析？
Critical path analysis is a network-based planning technique used to identify the sequence of activities that determines the shortest possible duration of a project. It shows which activities must be completed on time and which activities have spare time, called float.
关键路径分析是一种基于网络的计划技术，用于确定决定项目最短工期的活动顺序。它显示哪些活动必须按时完成，以及哪些活动有富余时间，即浮动时间。
Q5. Define ‘earliest start time’ and ‘total float’. | 定义“最早开始时间”和“总浮动时间”。
Earliest start time (EST) is the earliest time an activity can begin after all preceding activities have been completed. Total float is the amount of time an activity can be delayed without delaying the whole project. It is calculated as latest finish time – duration – earliest start time.
最早开始时间是指所有前置活动完成后，某项活动可以开始的最早时间。总浮动时间是指某项活动可以延迟而不影响整个项目完成的时间。计算公式为：最迟完成时间 – 工期 – 最早开始时间。
Q6. Why is total float important to a project manager? | 为什么总浮动时间对项目经理很重要？
Total float helps a project manager see which activities can be delayed safely and which cannot. It allows resources to be moved from non-critical activities to critical ones without affecting the project deadline. It also supports contingency planning.
总浮动时间帮助项目经理了解哪些活动可以安全延迟、哪些不能。它允许将资源从非关键活动调配到关键活动，而不影响项目工期。它还有助于制定应急计划。
3. Drawing a Network Diagram | 绘制网络图
Q7. Use the following activity list to draw a network diagram. | 根据以下活动清单绘制网络图。
| Activity | 活动 | Duration (days) | 工期（天） | Preceded by | 前置活动 |
|---|---|---|
| A | 3 | – |
| B | 4 | – |
| C | 2 | A |
| D | 1 | A |
| E | 5 | B, C |
The network diagram should have A and B starting at the first node. Activity A leads to a second node, from which C and D both begin. Activity B leads to a third node. C and B must both finish before E can start, so B and C feed into the same node. D ends at a separate node, and both D and E finish at the final project node.
网络图中，A 和 B 应从第一个节点开始。活动 A 指向第二个节点，C 和 D 都从该节点开始。活动 B 指向第三个节点。C 和 B 都必须完成后 E 才能开始，因此 B 和 C 汇入同一个节点。D 终到另一个节点，D 和 E 最终汇入项目的结束节点。
Q8. Why must a network diagram show logical dependencies clearly? | 为什么网络图必须清晰显示逻辑依赖关系？
Logical dependencies show the order in which activities must occur. If dependencies are drawn incorrectly, the diagram will give wrong timings and a misleading critical path. Clear dependencies also help managers identify which tasks must wait for others and which can run in parallel.
逻辑依赖关系显示活动必须发生的顺序。如果依赖关系绘制错误，图的时间计算就会出错，导致关键路径误导。清晰的依赖关系还能帮助管理者识别哪些任务必须等待其他任务完成，哪些任务可以并行开展。
4. Calculating Earliest Start and Finish Times | 计算最早开始与最早完成时间
Q9. Complete the table for the same activity list. Use days as the unit. | 根据上述活动清单完成下表。时间单位为天。
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