当前价值流图计算.doc

学习资料收集于网络，仅供参考P Updated definition of Value Stream 价值流定义While value streams may be defined broadly at the product level (e.g., large engines), or narrowly at the process level (e.g., canopy tack weld), manufacturing sections are the basic building blocks of the value streams. CPS requires the alignment of value stream definitions with manufacturing section definitions. Individual business units establish the section structure for quality management and certification, and financial management. Section managers, formerly referred to as frontline supervisors, combine responsibilities for managing teams of production employees, and value stream, quality and financial management.价值流包含广义上的产品级别 (比如大发动机) 或者狭义上的流程级别 (比如顶盖点焊接), 生产的各个区域/车间是基本的价值流元素。 卡特彼勒生产系统结合了价值流定义与生产区域的定义。各个业务单元为管理质量、认证和财务管理建立了自己相应的区域结构。车间经理，以前叫做一线主管，既要管理生产团队，也要管理价值流，质量和财务。Value Stream Mapping 价值流图Cycle Time 周期时间Cycle time is defined as a timed observation of how often a part or product is completed by a process. In other words, cycle time is the process exit rate.周期时间定义是经过一个流程某一零件或产品完成的时间。换言之，周期时间是流程产出率。When practical, multiple observations should be made. The lowest repeatable time should be used as observed cycle time. The operator should always be involved in determining cycle time. The observed cycle time is a measure of both value-added and non-value-added time in the process.观察周期时间是，应当按实际的、多次的观测取值。最短的重复时间通常被用做观测的周期时间值。操作者应当参与周期时间的测算。所观察的周期时间是一个流程内增殖和非增殖时间的总和。Measuring cycle time needs to be kept in appropriate context. If a batch of parts undergoes the same process step, then the observed cycle time applies to the full batch. The cycle time per piece is computed as observed cycle time divided by number of pieces in a batch.我们需要在某一特拟定的环境下测量计算周期时间。 如果一批次零件经过同一个流程步骤，那么观测到的周期时间为整个批次的周期时间。单件的周期时间则是总的周期时间除以这一批次零件数量。Cycle Time Piece = Cycle Time / Batch Size 单件的周期时间=周期时间/批量规模If multiple part numbers with comparable observed cycle times go through the same process step, calculate the weighted average (based on demand) cycle time and record it in the process box.如果多个件号零件也同样经过同一流程步骤，应当计加权平均周期时间（基于需求）并记录在流程图的周期时间框位置。Note: Record cycle time and batch size in the process box for each process step.备注：每一道工序都应在工序的周期时间框中记录周期时间和批量规模。Process Time 流程时间Process time is the time it takes for all the work elements to be completed. Process time includes both value-added and non-value-added steps. The concept of process time is closely related to cycle time. In many situations cycle time and process time are equivalent. Heat treat and paint process are typical examples when process time (floor-to-floor including load and unload) is longer than observed cycle time.流程时间是完成所有工作要素所需要的时间。流程时间包括增殖和非增殖的所有步骤。流程时间的概念和周期时间密切相关。在很多情况下两者是同一个数值。热处理和喷漆流程是非常典型的流程时间（从装载到卸载）明显比周期时间长的例子。Example 示例:Heat treat process takes 180 min. Every six minutes a batch of six parts exits the heat treat furnace. 热处理流程时间是180分钟。 加热炉每六分钟就完成一批产品，每批产品6件。Batch size = 6 pieces 批量大小=6件Cycle Time = 6 min 周期时间=6分Cycle Time Piece = 6 min / 6 pieces = 1 min 单件的周期时间=6分/6件=1分Process Time = 180 min 流程时间=180分Process time is how long the part is being worked on within the process; floor-to-floor time, including load and unload; one complete sequence of work elements. 流程时间是零件在某一流程内被处理的时间；时间间断，包括装夹和卸载的时间；是一个完整的工作要素序列。Total Product Cycle Time 产品总周期时间To represent the time component of the value stream, compute the total product cycle time or TCTP, which is an estimate of the time required for the product to move through a value stream at current demand levels. TCTP is a measure of the ability to meet customer demand. 产品总周期时间包含价值流所有时间元素，它是在当前需求水平下产品经过一个价值流所需要的时间。TCTp它用来衡量满足客户需求的能力。FormulaThe formula used to calculate total product cycle time is:TCTP = WIP / Current Customer Demand Rate公式用于计算产品总周期时间的公式是:TCTP = 在制品 / 当前客户需求率Total Demonstrated Cycle Time 实际总周期时间Total demonstrated cycle time or TCTD is a measure of the current ability of the value stream to produce. The calculation of TCTD is based on current levels of inventory and the demonstrated production rate (meaning the average exit rate of products to the customer).实际总周期时间用来衡量价值流当前的生产的能力。其计算TCTd要基于当前库存水平和当前实际生产率 （意指交付给客户的平均产品产出率）FormulaThe formula used to calculate total demonstrated cycle time is:TCTD = WIP / Demonstrated Exit Rate公式用于计算实际总周期时间公式是:TCTD =在制品/ 实际产品产出率Comparing TCTP to TCTD determines the gap in the current ability to meet a customer demand. Both TCTP and TCTD are recorded on the value stream map. 对比产品总周期时间和实际总周期时间从而展示出当前满足客户需求的能力的差距，两者都被记录在价值流图里。Cycle Efficiency 周期效率Process time and TCTP calculations are used to compute cycle efficiency, which is a ratio of the sum of process time to Total Product Cycle Time (TCTP)流程时间和产品总周期时间的结果用来计算周期效率，它是流程时间的总和与产品总周期时间的比值。FormulaThe formula used to calculate cycle efficiency is:Cycle efficiency = Sprocess time / TCTP公式用于计算周期效率的公式是:周期效率= S流程时间/ 产品总周期时间TCTPEffective Cycle Time 有效的周期时间To show the effect of wastes over time, CPS recommends calculating and analyzing effective cycle time. The OEE metric captures the percentage of wastes related to equipment downtime losses, performance losses and quality losses.为反应出时间浪费的影响，CPS推荐计算和分析有效周期时间。而OEE指标用于捕获设备停机时间损失、绩效和质量损失相关的浪费。FormulaThe formula for calculating effective cycle time is:Cycle Time EFFECTIVE = Cycle Time piece / %OEE公式用于计算有效周期时间:有效周期时间= 单件周期时间/ %设备综合效率OEEExample 示例: Assume observed cycle time per piece = 46 minutes.假设单件周期时间=46分钟 Assume OEE = 67% (includes wastes due to machine breakdowns, long changeover, re-work, etc.).OEE=67% （包含由于机器停机、长时间的换型和返工等产生的浪费）Effective Cycle Time = 46 / 67% = 46 / 0.67 = 68.6 minutes 有效周期时间=46/0.67=68.6分钟Include Effective Cycle Time on the TT/CT Bar Chart.