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The Strategos Guide To Value Stream and Process Mapping goes far beyond symbols and arrows. In over 163 pages it tells the reader not only how to do it but what to do with it. More info...

Strategos Guide to Value Stream & Process Mapping

Also...

Guide to Cycle Counting

Facilities & Workplace Design

Warehouse Planning Guide

Human Side of Lean Video


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Designing Workcells & Micro-Layouts

Cellular Manufacturing

Workcells and Cellular Manufacturing are at the heart of Lean Manufacturing. Their benefits are many and varied. They increase productivity and quality. Cells simplify material flow, management and even accounting systems.

Workcells appear simple. But beneath this deceptive simplicity are sophisticated Socio-Technical Systems. Proper functioning depends on subtle interactions of people and equipment. Each element must fit with the others in a smoothly functioning, self-regulating and self-improving operation.

Proper  design of manufacturing workcells is an engineering problem. Like any other engineering design, it proceeds through a logical sequence of steps. At each step, the designers make compromises between conflicting requirements or technical limitations. Doing it well requires a deep and profound knowledge of the elements of a workcell, their functions, and their interactions.

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Facilities & Workplace Design

Quarterman Lee, Arild Amundsen, William Nelson & Herbert Tuttle

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The links below take you to the detail steps of cell design. An experienced designer performs many of these steps informally or just mentally. The process is not as complex or lengthy as the charts indicate. However, failure to perform a step results in design by accident, a risky proposition.

You can find a complete explanation of this in Mr. Lee's book, "Facilities and Workplace Design - An Illustrated Guide."  Next Page

Four Tasks of Cell Design

Step Description Key Issues

Hover To Enlarge

Cell Design 1

Select The Products

The goal of product selection is to find compatible families of products that a group of machines can process without undo changeovers or other difficulties.  Many difficulties result from attempting too much variety. Important tools are Process Mapping and Group Technology.

Which products belong together in a workcell?

What is the design production rate for the cell?

Should we have reserve capacity?

Select The Products
Select The Products

Tasks:

1. Obtain Forecasts & Product Profiles

2. Obtain Current/Proposed Routings

3. Prepare Product Profiles and Forecast Charts

4. Chart Processes

5. Analyze Forecasts and Profiles

6. Less than 20 Items?

7. Chart Each Item

8. Less than 200 Items?

9. Less than 20 Unique Routes?

10. Production Flow Analysis

11. Code & Classify

12. Identify Preliminary Families

Products

Cell Design 2

Engineer The Process

Engineering the process requires a deep understanding of every process event as well as the times required for setup, personnel activities and machine cycles. From this we calculate the number of people required and the number of machines or workstations.

What process steps do we need?

What is the best sequence of steps?

What equipment should we employ?

How much equipment of each type?

How many people do we need?

What lot size is appropriate?

Engineer The Process
Engineer The Process

Tasks:

    13. Select preliminary processes and Equipment

    14. Refine the process

    15. Estimate setup times

    16. Estimate equipment times

    17. Estimate person times

    18. Estimate process times

    19. Calculate equipment requirements and personnel requirements

    20. Select preliminary lot size

Process charts

time study

lot size

Cell Design 3

Define The Infrastructure

Infrastructural elements support the process but do not touch the product. They are many and varied. Examples are:

  • Containers

  • Scheduling

  • Balance Methods

  • Motivation

Infrastructure is intangible and cell designs often fail due to lack of awareness about it.

What methods for material handling?

How do we balance the workload?

How do we schedule production?

How much Work In Process is necessary?

How do we motivate people?

How do we assure quality?

Define Infrastructure
Define Infrastructure

Tasks:

23. Identify external containers

24. Check Compatibility

25. Identify external handling equipment

26. Identify internal production control method

27. Identify people balance method

28. Check Compatibility

29. Identify Quality Assurance methods

30. Identify internal production control method

31. Check Compatibility

32. Identify internal lot size

33. Assign tasks & identify skill requirements

34. Check Internal-External consistency

35. Define supervisory approach

36. Identify compensation method

37. Identify equipment balance method

38. document with Operations Plan

39. Identify Choose internal containers

Cell Design 4

Layout The Workcell

The fourth task in workcell design is the physical layout. This is often straightforward if the previous tasks have been done thoughtfully. The Task Procedure diagrams can often be simplified. In many cases you may start with the process chart and move directly to a layout. 

What is the best physical arrangement?

How do we handle external constraints?

How do we integrate with the overall layout?

Layout the Cell

Layout the Cell

Tasks:

  40. Define Space Planning Units

  41. Rate Affinities

  42. Develop Configuration Diagram

  43. Design The Layout

Workcell Layout

 

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