1. Process Analysis
流程分析

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Process Analysis
Process Analysis 流程分析
Process Flowcharting 流程图的绘制方法
Types of Processes 流程类型
Process Performance Metrics 流程绩效评 价
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3. Process Analysis Terms 基本术语
Process: Is any part of an organization that takes inputs and transforms them into outputs.
Cycle Time: Is the average successive time between completions of successive units.
Utilization: Is the ratio of the time that a resource is actually activated relative to the time that it is available for use.
流程/步骤
节拍/周期
时间利用率
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4. Other Process Terminology
Bottleneck
Occurs when the limited capacity of a process causes work to pile up or become unevenly distributed in the flow of a process
If an employee works too slow in a multi-stage process, work will begin to pile up in front of that employee. In this case, the employee represents the limited capacity causing the bottleneck.
Pacing
Refers to the fixed timing of the movement of items through the process 瓶颈
节拍(?) / 定时 4

5. Process Flowcharting 流程图的绘制方法
Process flowcharting is the use of a diagram to present the major elements of a process.
The basic elements can include
tasks or operations,
flows of materials or customers,
decision points,
and storage areas or queues.
It is an ideal methodology by which to begin analyzing a process.
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6. Flowchart Symbols 流程图符号
Tasks or operations
任务或操作
Examples: Giving an admission ticket to a customer, installing a engine in a car, etc.
Examples: How much change should be given to a customer, which wrench should be used, etc.
Decision Points
决策点
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7. Flowchart Symbols (Continued)
Storage areas or queues
库存或排队
Examples: Sheds, lines of people waiting for a service, etc.
Examples: Customers moving to the a seat, mechanic getting a tool, etc.
Flows of materials or customers
物流或顾客流动
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8. Example: Flowchart of Student Going to School
Yes
Go to school today?
Drive to school
Walk to class No
Goof off
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9. Multistage Process 多阶段的流程
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10. Multistage Process with Buffer 具有库存的多阶段流程
缓冲器
Stage 1
Stage 2
Starving
Blocking
Bottleneck
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A buffer refers to a storage area between stages where the output of a stage is placed prior to being used in a downstream
stage
Blocking
Occurs when the activities in a stage must stop because there is no place to deposit the item just completed
If there is no room for an employee to place a unit of work down, the employee will hold on to it and not able to continue working on the next unit
Starving
Occurs when the activities in a stage must stop because there is no work
If an employee is waiting at a work station and no work is coming to the employee to process, the employee will remain idle until the next unit of work comes
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12. Types of Processes 流程类型
Conversion
Fabrication
Assembly
Testing
转化（如：冶炼）
制造（如：机械切削） 装配 测试 11 11

13. Types of Processes 流程类型
Make-to-order 为订单生产(MTO)
Only activated in response to an actual order.
Both work-in-process and finished goods inventory kept to a minimum.
Make-to-stock 为库存生产(MTS/MTI)
Process activated to meet expected or forecast demand.
Customer orders are served from target stocking level.
Hybrid processes 混合
combine the features of both MTO and MTS.
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14. Process Flow Structures 工艺流程结构
A process flow structure refers to how a factory organizes material flow using one or more processes technologies.
Robert Habert Hayes（贺氏） and Steven Wheetwright（威尔莱特）. Restoring out competitive edge:competing through manufacturing(New York: John Wiley & Sons ). P209.. 12 12

15. Process Flow Structures Hayes & Wheelwright 贺氏/威尔莱特
Job shop
Batch
Assembly Line
Continuous Flow
单件小批量生产 / 工艺专业化（宋国防译）
批量生产
装配线生产（大量）
连续流程生产（大量） 12 12

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生产类型的划分 （按生产的连续程度）
连续型：炼油厂24小时
重复型： 汽车流水线（零配件）
间断型：（零活混杂型 、 单项工程）
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17. 生产类型的划分-I （按产品品种和数量的需求）
大量大批生产
批量生产
单件小批量生产
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18. 生产类型的划分-II （按产品品种和数量的需求）
大量连续生产
订货间断生产系统
单项工程
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19. Process Performance Metrics 流程绩效评价 (基本时间）
Operation time = Setup time + Run time
运营时间 调整时间 作业时间
Throughput time = Average time for a unit to 全过程生产周期 move through the system
Cycle time = Average time between 节拍 completion of units
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20. Process Performance Metrics (Continued)
Throughput rate =
Cycle time
The output rate that the process is expected to produce during a period time
Process Velocity = Throughput time
(throughput ratio) Value-added time
产出率（生产速度）
工艺周转率
（任建标译）
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21. Process Performance Metrics (Continued)
Efficiency = Actual output
Standard Output
Productivity = Output
Input
Utilization = Time Activated
Time Available
生产效率
生产力
时间利用率
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22. Fang Aihua Wuhan University
Cycle Time Example
Suppose you had to produce 600 units in 80 hours to meet the demand requirements of a product. What is the cycle time to meet this demand requirement?
Answer: There are 4,800 minutes (60 minutes/hour x 80 hours) in 80 hours. So the average time between completions would have to be: Cycle time = 4,800/600 units = 8 minutes.
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23. Process Throughput Time Reduction 降低生产周期的方法
Perform activities in parallel. 平行作业
Change the sequence of activities. 变换次序
Reduce interruptions. 减少停顿 20

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Little’s Law 利特法则
Throughput time=WIP/Throughput rate
总生产周期=在制品数量/生产速度
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25. 补充术语 LT (Lead time) WIP (work-in-process) Lot size / batch size 提前期
MLT: manufacturing lead time
WIP (work-in-process)
Lot size / batch size
提前期
在制品 批量