Bạn lái xe cho dặm và dặm, hàng ngàn qua thùng màu da cam và tế bào hình nón, hàng trăm qua các rào cản và các dấu hiệu quá khứ, hàng chục cần cẩu, xe ủi đất đắt tiền, backhoes và, và như vậy dặm ngăn tạm thời cụ thể. Tuy nhiên, là hầu như không có bất kỳ người nào trong tầm nhìn. | CHAPTER How Important Are Schedules and Time Compression Have you ever driven along a highway where a construction project seemed to be going on forever You drive for miles and miles past thousands of orange barrels and cones past hundreds of barriers and signs past dozens of expensive cranes bulldozers backhoes and such and miles of temporary concrete dividers. Yet there are hardly any people in sight. Where are the workers Why are there 10 miles of detoured traffic and only 10 yards of active work Not only that but you drove by that spot six months ago and hardly anything has changed. Getting beyond your immediate frustration with the traffic slowdowns your ever-inquisitive mind drifts to the topic of waste. How much money is tied up in all of this paraphernalia How much money could be saved by expediting these projects as well as reducing the inconvenience to the driving public Period Costs and Hammocks The typical project will contain a combination of labor-based costs materials costs and other costs such as equipment rentals and supplies. Consider that many of these are period-based costs. That is the costs are associated with the duration of the use rather than the intensity or frequency of the use. 100 TIME-TO-MARKET 101 If we look at the highway type projects such as discussed above we can list several period-based costs. These would include field trailers office equipment including computers and phones earth-moving equipment and such. What about all of those orange barrels and cones They must represent a reasonably sized capital investment. What about foremen The longer the job the longer the cost. Good scheduling software will have a hammock function. A hammock is a type of task that does not have a fixed time duration. Instead it automatically calculates its duration from the tasks that it is associated with or group of tasks that the hammock spans . You can use the hammock function for all tasks that have resources or costs that are associated with
