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Value Stream Mapping,  Step-By-Step  

How To Do It; What To Do With It 

Present State Mapping

A Present State Map shows work processes as they currently exist. This is vital both to understand the need for change and to understand where opportunities lie. While Value Stream Maps appear complex, their construction is easy when taken in logical steps. These  illustrations show how. A broad-based team should perform this exercise.

Mapping Team

1. Draw customer, supplier and production control icons.

2. Enter customer requirements per month and per day. 3. Calculate daily production and container requirements.

vsm step 1
vsm step 1

4. Draw outbound shipping icon and truck with delivery frequency.

5. Draw inbound shipping icon, truck and delivery frequency.

vsm step 2
vsm step 2

6. Add process boxes, in sequence, left to right.

7. Add data boxes below. 

vsm step 3
vsm step 3

8. Add communication arrows. Note methods & frequencies.

9. Obtain process attributes. Add to data boxes.

10. Add operator symbols.

vsm step 4
vsm step 4

11. Add inventory locations and levels in days of demand & graph at bottom.

12. Add push, pull and FIFO icons.

13. Add other useful information.

vsm step 5
vsm step 5

14. Add working hours.

15. Add cycle and lead times

16. Calculate total cycle & lead time.

vsm step 6
vsm step 6

Mapping the Future State

A Future State Value Stream Map helps with the larger process of developing your Lean Manufacturing Strategy. It requires significant knowledge of Core Disciplines and other specific topics.

Designing a Future State requires more art, engineering and strategy than Present State mapping. On this page, we show mapping, but the background knowledge is in these other parts of our site.

Here, we use the example from above. After constructing the Present State Map, follow steps 1-7. The map below shows the final results. Note the large improvements in Lead Time, productivity and inventory reduction.

You can expect much discussion about details of implementation and feasibility of various options. This is normal. Our goal is to establish general feasibility, not to decide every detail of the design or to plan an implementation. The facilitator must maintain careful control over this type of digression.

Click on each thumbnail for an enlarged view and explanation.

0. Review Present State Map

Future State VSM-1
Future State VSM-1

Step 0

Review Present State Map and Transfer Information

Some information remains unchanged between the Present State map and possible Future State maps. Transfer this information such as customer requirements, supplier and customer to the Future State map.

At this time, the VSM team should review their Present State Map. This review should answer three questions:

  • Is the map essentially correct?

  • Does everyone on the team understand the map in all its detail?

  • Where are the major opportunity areas?

The teams under the facilitator’s guidance can only answer the first two questions. We have little advice here other than to question team members closely and discuss these questions thoroughly. If there is disagreement within the team on how to represent some items, you can simply note this disagreement. It is unnecessary to resolve every detail.

Major opportunities may be available where the following conditions exist:

1. Calculate Takt Time

Future State VSM-2
Future State VSM-2

Step 1

Calculate Takt Time

Future State VSM-2Takt time is the average time between production units necessary to meet customer demand. We use the available time divided by the required number of units from the previous example.

2. Identify Bottleneck Process

Future State VSM-3
Future State VSM-3

Step 2

Identify Bottleneck Process

work balancechartThe bottleneck process is the operation with the longest cycle time. In the example, this is machining at 44 seconds. The bottleneck is important because it: Determines total system output. Becomes the primary scheduling point A work balance chart (above) is helpful for steps 2 and 3. Cycle time is plotted on the vertical axis for each operation.

3. Lot Sizing & Setup Opportunities

Future State VSM-3
Future State VSM-3

Step 3

Identify Lot Sizing/Setup Opportunities

Setup Time ChartPresent lot size is 1000 pieces, about two day's production. This requires at least 3-6 days finished goods and prevents daily adjustments to mix or demand.

If the lot size were simply cut, it would allow faster response but additional setup time in machining would use available time. Machining could not meet the average customer requirements.

However, if a focused setup reduction is made on machining and setup becomes 20-30 minutes, a batch size of 500, or even 250 is feasible. The mapping team established this as a goal, noted by a Kaizen Burst.

4. Identify Potential Workcells

Future State VSM-4
Future State VSM-4

Step 4

Identify Potential Workcells

work balance chartThe balance chart shows cycle time for each of the five process steps. Machining and honing operations are closely balanced. Cycle times for clean/deburr, inspection and packaging are quite short in comparison.

The very short cycle times for clean/deburr and packaging indicate low utilization in a cell. However, inspection and packaging are manual operations that require little more than a workbench and hand tools. High equipment utilization is not critical.

Clean/deburr process is run on specialized equipment in a central area. If clean/deburr can be scaled down as a manual or semi-manual operation, it can go in the cell. This seems feasible and the team accepts that, somehow, it will be done.

It appears that three operators can run the cell. This is not a precise calculation. It only considers present cycle times and ignores setup.

Workcells are more involved than suggested here. However, our purpose is not to finalize details but make reasonable guesses about the general configuration. A Kaizen Burst identifies a need for more work.

5. Determine Kanban Locations

Future State VSM-6
Future State VSM-6

Step 5

Determine Kanban Locations

With a workcell for five processes, scheduling between them becomes a trivial case. They will be directly linked with continuous or small-batch flow. Kanban, internal to the cell, is unnecessary or becomes part of the detailed cell design.

Kanban does apply at two other locations:

  • Between cell and supplier

  • Between cell and customer

The detailed design of the kanban system is shown as a Kaizen burst. Inventory levels are current best estimates.

6. Establish Scheduling Methods

Future State VSM-7
Future State VSM-7

Step 6

Establish Scheduling Methods

Kanban and direct links now schedule all operations short term. Both the workcell and the supplier, however, need forecasts to plan staffing and possible changes in inventory levels. The map shows this monthly information flow.

 Purchasing must arrange for payment. They intend to do so with monthly blanket orders, also shown.

7. Calculate Lead and Cycle Times

Future State VSM-8
Future State VSM-8

Step 7

Calculate Lead and Cycle Time.

The final step in the Future State Map is to complete the timeline at bottom, and calculate Lead Time, Cycle Time and Work Time.

Results

In this example, the mapping team estimates a Lead Time reduction of 85% and a productivity increase of 25%. Inventory will decrease about 85%. Many additional, but unpredictable benefits are also likely.

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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