项目管理Reducing Project Duration.ppt

1、Chapter Nine: Reducing Project Duration,成本、质量与工期的关系图,9.1：Overview综述,Reasons: In recent years emphasis on time-to-market has taken on new importance because of intense global competition and rapid technological advances. The market imposes a project duration date. 近年来，由于激烈的市场竞争和快速的技术进步，对投放市场时间的强调具有了新

2、的重要性，市场强加了项目一个完成日期。(291-2-1) Incentive contracts in partnering arrangements can make reduction of project time rewardingusually for both the project contractor and owner. (291-3-1) Another reason for reducing project time occurs when unforeseen delays. (291-4-1),项目进度的表达形式1带有日历的项目网络图,项目进度的表达形式2时间坐标网络

3、图,项目进度的表达形式3条形图或甘特图,项目进度的表达形式4里程碑事件,项目进度的表达形式5里程碑图,项目进度的表达形式6项目计划表,项目进度的表达形式7项目行动计划表,There are few circumstances in which a project manager or owner would not wish to reduce the time to complete a project. (289-3-1)很少有项目经理或业主不愿意缩短项目完成时间。 The manager faces a cost-time trade-off problem. (289-3-3)管理者面

4、对着一种成本时间权衡问题。 Cost-time situations focus on reducing the critical path that determines the project completion date. (289-3-5)成本时间关系的焦点在于缩短决定项目完成日期的关键路径。,the challenge for the project manager is to use a quick, logical method to compare the benefits of reducing project time with cost. (291-7-2)项目经理所面

5、临的挑战是使用快速合理的方法将缩短项目时间的收益和成本进行比较。 When sound, logical methods are absent, it is difficult to isolate those activities that will have the greatest impact on reducing project time at least cost. (291-7-3)在找不到合理有效的方法时，在最小成本下很难分辨出对缩短项目时间影响最大的那些活动。,This chapter describes a procedure for identifying the co

6、sts of reducing project time so that comparisons can be made with the benefits of getting the project completed sooner. (291-8)本章描述了一种识别缩短项目时间的成本的过程，这样就可以与项目更快完成获得的收益进行比较。 The method requires gathering direct and indirect costs for specific project durations. Critical activities are searched to find

7、 the lowest direct-cost activities that shorten the project duration. Total cost for specific project durations are computed and then compared with the benefits of reducing project timebefore the project begins or while it is progress.,时间成本优化,概念： 是指在成本最低的条件下，确定最佳工期；或在最短工期的条件下，确定最佳成本。 思路： 项目总成本=直接成本+

8、间接成本,9.2: Project cost-duration graph项目成本时间图,Explanation Constructing a project cost-duration graph,9.2.1: Explanation,the general nature of project costs : (291-9) The total cost for each duration is the sum of the indirect and direct costs.每种时间长度的总成本是直接成本和间接成本的总合。 Indirect costs continue for the l

9、ife of the project. Hence, any reduction in project duration means a reduction in indirect costs.间接成本在项目过程中一直持续，因此，项目时间长度的任何削减都意味着间接成本的降低。 Direct costs grow at an increasing rate as the project duration is reduced from its original planned duration.随着项目时间长度在原计划水平上的下降，直接成本以加速度增加。,Project Cost-Time Gr

10、aph项目成本-时间图,indirect costs: (292-2) generally represent overhead costs. (292-2-1) Indirect costs vary directly with time. that is, any reduction in time should result in a reduction of indirect costs. (292-2-3)随着时间变动，时间上的任何减少都会导致间接成本的降低。 Direct costs: (292-3) Direct costs commonly represent labor, m

11、aterials, equipment, and sometimes subcontractors. (292-3-1)一般包括劳动力、原材料、设备，有时还包括转包商。 Direct costs are assigned directly to a work package and activity. (292-3-2)直接分派给各个工作包和活动。,变更时间与所付代价关系图,9.2.2: Constructing a project cost-duration graph 构建时间成本图,Three major steps: (293-2) Find total direct costs fo

12、r selected project durations. Find total indirect costs for selected project durations. Sum direct and indirect costs for these selected durations.,Major details:,Determining the activities to shorten: Managers need to look for critical activities that can be shortened with the smallest increase in

13、cost per unit of time. (293-3-4) The rationale for selecting critical activities depends on identifying the activitys normal and crash times and corresponding costs. (293-3-5),Terms: Shortening an activity is called crashing. The shortest possible time an activity can realistically be completed in i

14、s called its crash time. 现实中完成活动可能的最短时间叫压缩时间。 The direct cost for completing an activity in its crash time is called crash cost. 在压缩时间内完成活动的直接成本叫压缩成本。,Knowing the slope of activities allows managers to compare which critical activities to shorten. The less steep the cost slope of an activity, the le

15、ss it costs to shorten one time period; a steeper slope means it will cost more to shorten one time unit. (293-5) The cost per unit of time or slope for any activity is computed by the following equation: (293-5) Cost sloperise/run =(crash cost-normal cost) / (normal time-crash time) =(cc-nc) / (nt-

16、ct),Activity Graph活动图,The total direct cost for each specific compressed project duration must be found.(294)一定要找出每个特定的压缩项目时间长度的总直接成本。 With the total direct costs for the array of specific project durations found, the next step is to collect the indirect costs for these same durations. These costs a

17、re typically a rate per day and are easily obtained from the accounting department. (296-2-1)间接成本是一个每日比率，很容易从会计部门获得。,Cost-Time Trade-Off Example,Cost-Time Trade-Off Example (continued),各时间长度对应的成本例表,Project Cost-Time Graph,Advantage： The creation of such a graph keeps the importance of indirect costs

18、 in the forefront of decision making. (297-1-2)这种图将间接成本的重要性放在了决策人员面前。 Disadvantage: Linearity assumption is impractice.,附有正常和应急时间及成本的网络图,缩短工期的单位时间加急成本可用如下公式计算： 每项活动的每周加急成本可根据上述公式分别计算出来： 活动A： 6 000元周 活动B：10 000元周 活动C： 5 000元周 活动D： 6 000元周,单位时间加急成本,时间成本平衡法的举例,9.2.3: Choice of activities to crash revis

19、ited对被压缩的活动选择,The cost-time crashing method relies on choosing the cheapest method for reducing the duration of the project. (298-3-1)成本时间压缩依赖于选择最廉价的方法来缩短项目期限。 There are other factors that should be assessed beyond simply cost: First, the timing of activities needs to be considered. 活动的时效。 A second

20、consideration is the impact crashing would have on the morale and motivation of the project team.对团队的士气和工作动力的影响。 Finally, the inherent risks involved in crashing particular activities need to be considered.内在风险。,9.2.4: time reduction decisions and sensitivity时间压缩的决策和敏感度,how far to reduce the project

21、 time from the normal time toward the optimum depends on the sensitivity of the project network. A network is sensitive if it has several critical or near-critical paths. (300-2-1)要使项目时间从正常时间变为最优时间，应该缩减到何种程度取决于项目网络的敏感度。敏感的网络是指具有多种关键路径或接近关键的路径。,Sensitive network require careful analysis. The bottom l

22、ine is that compression of projects with several near-critical paths reduces scheduling flexibility and increases the risk of delaying the project. (300-2-8)对于敏感的网络需要进行细致的分析。 The outcome of such analysis will probably suggest only a partial movement from the normal time toward the optimum time. (300

23、-2-11)这种分析的结果可能说明只能从正常时间向最优时间进行部分调整。 there is a positive situation where moving toward the optimum time can result in very real, large savingsthis occurs when the network is insensitive. (300-3-1)一种较好的情况是，向最优时间的调整实际上可以导致大量节省这发生在网络不敏感的时候。 Insensitive networks with high indirect costs can produce larg

24、e savings. (300-4-7)具有高间接成本的不敏感网络可以带来巨大的节省。,9.3: Options for accelerating project completion提前完成项目的措施,Several of methods: (300) Adding resource增加资源 The most common method for shortening project time is to assign additional staff and equipment to activities.最常用的方法是为活动分派额外的人力和设备。 outsourcing project w

25、ork外包项目 Scheduling overtime安排加班 The easiest way to add more labor to a project is not to add more people, but to schedule overtime. 增加人手的最简单的办法不是增加新人，而是安排加班。 Establish a core project team建立核心项目团队 One of the advantages of creating a dedicated core team to complete a project is speed.,do it twice-fast

26、 and correctly再做一次又快又好 Fast-tracking快速追踪 Critical-chain关键链 Critical-chain (c-c) project management is designed to accelerate project completion.关键链项目管理能够加快项目进度。 brainstorming time savers节省时间的头脑风暴 Reducing project scope缩小项目范围 the key to reducing a project scope without reducing value is to reassess t

27、he true specifications of the project. (304-2-1)缩小项目范围却不减少项目价值的关键是重新评估项目真实的规格要求。 calculating the savings of reduced project scope begins with the work breakdown structure. (304-3-1)计算缩小项目范围带来的节省要从工作分解结构开始。 Phase project deliver 项目阶段性交付 Compromise quality牺牲质量,What if cost reduction, not time, is the issue?当成本比时间更重要时,below are some of the more commonly used options for cutting costs: (305) Reduce project scope缩小项目范围 Have owner take on more responsibility让业主承担更多责任 Outsourcing project activities or even the entire project 外包项目活动