机械设计的基本原理1.10
Deterministic Design: Schedules
确定性设计：时间表
Although there are many different elaborate models of how designs develop, most would agree that overall there are essentially three basic phases to the development of products: Strategy & Concept, Detailed Engineering & Development, and Integration & Test. Each of these phases, when executed properly, take about a third of the total development time. Too much or too little time spent on one of the phases means that you will likely be rushed in one of the other phases, and quality and performance will suffer.
虽然设计演化的模型有很多，但是所有模型基本都由三个阶段组成：策略和概念，详细设计和研究，以及集成和测试。每个设计阶段正确执行的话，都应该占设计周期的1/3左右。在某个阶段耗费过多或过少时间，都意味着另外几个设计阶段的执行太仓促，从而设计产品的质量和性能肯定会大打折扣。
There are many different detailed methodologies ranging from House of Quality1 to Rapid Product Development2 to Axiomatic Design3; however, all of them require a sequencing of events and thus all require the engineer to maintain a schedule. Needless to say, there are an equally large number of scheduling methods, but at this phase, the method is not as important as the net effect. What matters is that the total time allotted for completion of the project be partitioned to each of the basic phases, and then each phase be further partitioned to ensure that an appropriate amount of time is allotted to each task. A simple table often thus suffices to outline what needs to be done, which by the way, is the same process used to manage the creation of a major written work, or the composition of a symphony, or the cooking of a large meal, or creation of a major software program! The patterns of best design practice repeat!
虽然有诸如质量屋、快速原型设计和公理设计等设计方法论，但是这些设计方法都需要工程师们按部就班的按照时间计划执行各项事件。同样的，时间管理的方法也有很多，但是实际效果远比方法本身更重要。对于时间管理，项目整体完成时限需要合理分配给每个基本的设计阶段，然后每个设计阶段的时间都合理的分配给相应的任务。一个简单的表格就足以勾勒出计划的内容，就如同作家写作、作曲家写曲子、厨师烧菜或者程序员编程一样。机械设计的最佳工程实践始终贯穿于整个设计过程，融会贯通。
Given a project that is already broken up into thirds, the best way to decide how time should be spent in each of the phases is to assess the cost/performance issues associated with the project. Starting with a fundamental assessment of the physics of the problem and of possible solutions, one is likely to identify potential leading edge strategies, and possibly even a disruptive technology. These potential strategies should be investigated first, and then a detailed development schedule can then be created.
分配好时间后，就要深入的决定每个设计阶段任务的时间了。最佳的方式，永远是通过评价成本/收益问题来决定。首先从基本的原理出发，找到问题的物理模型和可能的解决方案。一般工程师们都会找到潜在的技术领先类的解决策略，甚至是颠覆性的技术方案。这些潜在的技术方案都应该仔细调查研究，然后才能讨论更细节的研发计划和制造装配。
Each of the thirds can be thirdified into thirdlets! Given a 12 week development process for a robot to be entered into a design contest, the first trimester is allotted to developing strategies and concepts. The first week should be devoted to developing a deep understanding of the problem and using this understanding to create strategies ranging from shoot-from-the-hip instinct ideas, to ideas driven and guided by analysis. The second week should be spent doing experiments and more detailed calculations to weed out lame or super risky ideas, and evolving a leading edge strategy. The third week is then spent generating, creating, and evolving concepts to arrive at a best concept for development. The fourth week is float time, It might be needed because more than expected experiments and analysis was required during the third week; or a leading edge concept might indeed have been identified, and then the next trimester can be entered early and you can get ahead of schedule!
对于设计的三个阶段，都可以更细分为下一层次每个阶段对应的其他子阶段。准备一份12周的参赛机器人研发过程计划，其中第一个学期用来研究方案和对策。第一周的设计，需要深入理解问题本身，通过理解促进方案和对策的制定。无论是直觉的解决方案，抑或是客观参数分析得出的解决方案，都是可以的。第二周的设计，需要通过实验或者详细的计算来剔除可行性较差或者风险太高的方案，这样才能找到解决问题的技术领先类方案。第三周的设计，通过演化和创造，应该能找到最佳的解决方案了。接下来一周，是浮动时间。有可能是用来做更多的实验或者测试，或者是你已经发现了技术领先类的解，这样你就可以提早进入下一个学期的日程了。
The second trimester is for detailed engineering and development. The first two weeks are for dividing the concept up into modules and for developing and testing the most risky module. Accordingly, at the end of the sixth week of the project, the most risky module should actually be all designed and ideally a Bench Level Prototype completed and tested. The next two weeks are for completing the detailed engineering of the remaining modules. If there is any uncertainty, a module can be engineered and a Bench Level Prototype can also be designed and tested.
第二学期主要是详细设计和研发阶段。前两周需要把方案细分成不同的机械模块，并对最不确定的风险模块进行测试和检验。所以，在第六周结束前，风险模块已经完成所有设计。这样，最好的情况是，你可以完成原型机的实验和检测。接下来两周，用以完成余下模块的详细设计。如果还有不清楚的地方，模块可以同样制作原型机，进行测试和研发。
The first two weeks of the third trimester are for completion and testing of remaining modules. The eleventh week is for integration and testing of the modules, and the twelfth week is for continual use to find any flaws that may remain. If all goes according to schedule, and it will if one is careful to follow a deterministic design process, the entire process of conceiving of an idea, growing it, and then giving birth to it will be a joyous happy experience!
第三学期的前两周，用以完成剩下模块的测试和检测。第十一周的时候，所有模块就可以进行集成和调试了。到了第十二周，可以对整个设备的问题进行发现和排除。如果所有进程都按计划进行，而且你采用了确定性设计的话，那么整个找出方案、设计方案并亲手装配方案的过程将是你无比愉悦的过程。
Remember, “It takes 9 months to gestate a human baby, no matter how many women are assigned the task!”4
切记“孕育生命都需要九个月的时间，无论是多少妇女想要完成这个任务，都要遵守。”
Carefully read through ALL of the milestones required for the development of your project and develop a strong internal urge and commitment to work deterministically and to adhere to the schedule. Start off on the right foot by completing Milestone ONE as soon as possible! Engineers who consistently miss milestones will soon find themselves looking for burger flipping
仔细阅读时间表上的各个节点，全身心的投入到设计中去吧。尽快按照时间节点完成设计才是正确的方向，那些总是错过时间节点的设计师最后等待他们的只有低廉的薪水。
1.K. Otto, K. Wood, Product Design, Prentice Hall, Upper Saddle River, NJ, USA 2001
2.Karl T. Ulrich, Steveen D. Eppinger Product Design And Development, 2000 The McGraw-Hill Companies, Inc. Boston, MA, USA
3.Nam. P. Suh, Axiomatic Design, Advances and Applications, 2001 Oxford University Press, New York
4.Frederick P. Brooks Jr. The Mythical Man-Month, 1995 Addison-Wesley Longman, Inc. Reading, MA. USA
