Introduction 

★What does time mean？

Time is an indispensable（不可或缺的） resource for any project. Its significance（意义） for project management is reflected in two aspects: Every project must face a final delivery date（最后的交付日期）, which constitutes one of the three constraints（约束） of the project. All management activities are inevitably carried out around the time coordinate（时间坐标）, which provides an important quantitative index（量化指标） and ruler for the project. Project time management is the most characteristic part of project management knowledge system. Many contents of quality, cost, procurement, human resources and risk management overlap（重叠） with Business Administration（工商管理） ,but only time management is the unique content of project management.

Pondering on time（关于时间的沉思）

★what does schedule mean?  (noun ;  verb  名词或者动词）

Scueduling（工作计划，日程安排） is a scientific and artistic management activity around time and other resources. 

Scheduling a business meeting

▶In project management, a schedule is the tool most commonly used to plan the project step by step. By systematically analyzing each activity and its relationship to the ones that come before and after it, the project manager can build the project on paper before committing resources to it.

▶Schedules are essential to the successful execution（执行） of any complex project. They are not unique to construction but are found in many industries, including business, manufacturing, and publishing. Whenever people, equipment, materials, and organizations are brought together and directed toward a common goal, they need a common tool that will identify how resources are going to be committed.

▶Construction schedules are considered acceptable in court when arguments occur over project completion or delivery dates or in the formal coordination of project participants. Conflicts can occur over many issues during the course of a construction project. Design changes, poor weather conditions, labor actions, and miscommunication of deliveries, are all a common basis for conflicts. If the parties involved are unable to work out their differences through negotiation or arbitration, the alternative is to use the court system. At the court level, judgments that involve time and project coordination are made using a network schedule.

▶Schedules establish the start, duration（持续时间）, and completion dates of a project or a task. They let people and organizations know in advance when to expect a certain action to take place. Contractors, and suppliers, to stay profitable, have many jobs that must be organized and planned. The start and completion date of a particular job is essential information because it allows them to determine whether or not the job can be accomplished in the context of their other work. Knowing precisely how long an activity will take also has substantial cost implications. (for example: Scheduled start dates determine when goods and services need to be brought to the job site, when a workforce needs to be mobilized, and when equipment rentals begin. this date is critical to the accurate pricing of the project. a delay in the start of the project could significantly affect the cost of a material and the rate at which labor can be bought.)

Scheduling Throughout the Project

 ★Preconstruction Planning(建造前规划）

▶Scheduling is a key activity during the preconstruction stage. the initial schedule is a tool for the project team to begin to make intelligent management decisions.The scheduling process during preconstruction should be viewed as an opportunity to design and build the project on paper before actual construction. this allows all project parties to visualize the process and make all the necessary provisions（准备） to properly coordinate it. the team may now decide to order key long-lead purchase items（关键的长周期的采购项目） such as structural steel, elevators, compressors（压缩机）, or electrical switchgear（开关）.

▶During preconstruction, the first schedule is assembled with little information. As the project evolves, the managers will continually refine（优化） the schedule to optimize the project activity duration, creating efficiencies in time and money.

▶In summary, scheduling during preconstruction provides the project team with the necessary information to properly plan and coordinate the entire design/build process.

 ★Construction Scheduling（施工进度规划）

▶Project schedules are essential to the successful coordination of a project’s day-to-day activities. Material deliveries, equipment, and people are all orchestrated（策划，编排） through the schedule.

▶As a project progresses, delays inevitably occur. The project manager’s job is to effectively deal with these delays and to anticipate them as much as possible. If problems never occurred on a project, the project manager’s role would be less critical. It is the intelligent response to bad weather, equipment failures, strikes, design errors, and omissions that separates the well-managed project from the disaster.

▶During construction, a CPM（关键路径法） schedule may record the actual daily activities at the site. The schedule  is often placed on the wall of the job-site trailer（活动房屋）, where it is clearly visible to all the tradespeople. The project manager can graphically record progress, often with colored markers（马克笔） and symbols（符号）. Not only does the schedule record issues for the day, but it can also help the manager anticipate future problems. Written documentation in a court of law has much more weight than does someone’s memory.

 ★Postconstruction Scheduling（完工规划）

▶As a project nears completion, the ultimate user becomes more involved in the construction process. In many projects the owner begins to occupy the facility before construction is complete.

▶Most projects require testing and acceptance of equipment, and training of people who will ultimately use and maintain the equipment. At the same time, deficiencies（缺陷不足） need to be corrected and incomplete work closed out. All need to be coordinated and controlled to occur smoothly.

▶An important function for the project team is to close the books on the project. If the people and companies involved are to learn from the project experience, they must record its actual events. Unplanned events such as coordination difficulties, production rate differences, or delivery delays should all be recorded. These actual data should be stored so that, in the future, better planning and scheduling can occur. Record keeping is also important in case of future claims or disputes.

Reviewing questions(复习思考):

1. Describe how and why schedules are used in the preconstruction and construction stages of a project.