Reference no: EM133169694

Our PB&J (yes, we make peanut butter and jelly sandwiches) manufacturing company goes by the name of Seinfeld and Kramer Inc. 

Step 1: Calculate TAKT time. 

(TAKT time? Use your text!)

 In our example, we have a daily demand of 700 pieces (sandwiches) with the following arrangement.

• Hours per shift: 8
• Break minutes per shift: 30
• Shifts per day: 1
• Days per week: 5

The TAKT time is 39 seconds per piece. In other words, we need to produce a completed PB&J sandwich every 39 seconds to satisfy customer demand

The best value stream maps have eraser marks all over them. Please, I beg you; don't use a pen when drawing these.

After studying the KB&R manufacturing process for an afternoon, we learned that each process step is staffed with one operator. We also collected cycle time information at each stage. 

Your process steps are:

Peanut Butter Application (Total C/T = 25 seconds)

Jelly Application (C/T = 30 seconds)

Packaging (Total C/T = 42 seconds)

Step 8: Add the Inventory/Wait Times. 

Once you have all the process and data boxes in, it's time to add in inventory and waiting times. These are the little yellow triangles with an "I" in the middle.

For an inventory, we count the number of pieces in between the processes and note them under the triangle.

Wait Times:

Peanut Butter Application to Jelly Application (359 pieces in wait time)

Jelly Application to Packaging Application (486 pieces in wait time)

Packaging to Shipping (128 pieces in wait time)

We also want to convert these pieces into days' supply. To do this, we divide the number of pieces by the average daily demand (which we used to calculate TAKT time).

So, if your average daily demand is ten pieces and you count 20 pieces of inventory in between process step A and process step B you have two days' supply (20 pieces dived by 10pieces per day) in between the two processes. We will note this number on our timeline (to be added in a future step).

Calculate the supply (in days) you have in wait time. (This is the only required calculation).

We count two pieces of bread as one subassembly since they move together down the production line.

We are not accounting for the peanut butter and jelly "raw material" at this point since Seinfeld and Kramer's expert supply chain team negotiated a killer consignment stock deal with Sam's Club, so this inventory is quite low on the line.

During the study, we learned that, as one example, there were 486 sub-assemblies (972 pieces of bread) in between the jelly application and packaging stations. This data equates to 0.69 days' supply            (486 units / 700 daily demand). (This is a hint).

During the walkthrough of the process, we noticed that each process step seemed to be working in isolation. In other words, the employee working at the peanut butter application seemed to produce as many units as she could and then pushed them along to the jelly application process.

This "push" process is found in just about every mass production process known to humans. When we see this pushing action, we note it on a VSM with a dashed line through the yellow inventory symbol.

Step 9: Draw in the information flow. 

This step is what separates a VSM from traditional process maps, in my opinion. You see, in addition to learning about how material flows, we also want to understand how information flows.

For example, we want to know it information flow electronically. If so, we use a lighting bolt looking arrowed line. Is it communicated manually? If so, we use a straight arrowed line.

During this step, we also draw in our production control box. For many, this box will include the letters "MRP" in it. In most mass production systems we typically see several manual information (straight) lines coming out of the MRP box aimed straight at each process step box.

At Seinfeld and Kramer, we learned that production schedules each process step in isolation. In other words, each work station gets its unique production schedule. We draw this using straight "manual" information lines.

We also add in the information flow from our customers as well as to our suppliers. We learned that Seinfeld and Kramer's customer sends 30 days electronic forecasts as well as daily electronic orders. Conversely, PB&J sends its bread supplier an electronic weekly forecast.

Step 10: Add in the timeline. 

We can now add the timeline to the bottom of the value stream map. This saw tooth looking line helps us separate the value-added cycle time (taken from data boxes) from the non value-added time (days' or hours' supply info).

The last step in the process is to sum up all the "value-add" cycle times and note them at the end of the timeline. Likewise, we also sum up the "inventory" times and note that on the timeline.