Value Stream Map Data Box

Quick reference

• 00:04 Hello, I'm Ray Sheen.
• 00:06 The value stream maps are also characterized by the value stream data box
• 00:10 that is associated with each step.
• 00:12 Let's take a closer look.
• 00:14 >> A major element in value stream mapping is tracking data at each
• 00:19 step in the value stream.
• 00:21 Recall that goal of lean analysis is to eliminate waste.
• 00:25 Therefore, the data we collect and
• 00:27 record on the value stream map would be something about waste in the process.
• 00:32 Usually, that means wasted time or wasted effort.
• 00:36 Wasted time will focus on the flow elements.
• 00:39 We want to find when we do activities that do not add value, these are wasted time.
• 00:45 Also, we want to find bottlenecks and delays.
• 00:48 Those, too, are wasted time.
• 00:51 One other comment, when doing time analysis in a value stream map,
• 00:56 we use a 7 day week and a 24 hour clock.
• 00:59 Even though you may only be working one shift five days a week,
• 01:03 we count all the time.
• 01:04 That's because the customer who is waiting for
• 01:07 the result must deal with all of the time, not just your work time.
• 01:12 The wasted effort in the value stream map data box is focused on yield, and
• 01:16 again, wasted activity.
• 01:18 But looking at the yield, making a part or doing a step in a process
• 01:23 that is then scrapped or must be redone is wasted effort.
• 01:27 If done correctly the first time, no extra effort would be required.
• 01:32 One last point about the value stream map,
• 01:35 we will put the data box right in the value stream map so
• 01:39 that the picture of the flow and the data are linked together.
• 01:44 A data box is just that,
• 01:45 a set of boxes on your value stream map that contain items of data.
• 01:50 Typically, on a value stream map,
• 01:53 every step will have a data box just below that step.
• 01:57 Each data box contains the measurable data that is associated with that step.
• 02:02 Now, to make it easy to read the map, every data box on the map will have
• 02:06 the exact same list of data items in the same sequence in their box.
• 02:11 Which data items listed may change from map to map, but
• 02:15 the data items are consistent within a value stream map.
• 02:19 Normally, there'll be at least one time-based element, such as total time or
• 02:23 value-added time.
• 02:24 Normally, there's at least one resource-based element,
• 02:27 such as the number of people or the number of units of equipment at that step.
• 02:31 And normally, there will be at least one quality-based data element item,
• 02:36 such as first pass yield.
• 02:37 In my experience,
• 02:39 most data boxes will have between three to eight data items in the box.
• 02:44 Your business may have a standard data box format.
• 02:47 If so, use it, if not, work with your organization's Black Belt to
• 02:52 decide what are the appropriate elements for your process.
• 02:56 Again, try to have time, resources, and quality elements.
• 03:01 So let's look at a simple example.
• 03:04 As you see, I'm showing four steps of a value stream map.
• 03:08 Under each of these steps is the data box, and below the data box is a time ladder.
• 03:14 More about that in just a moment.
• 03:16 When you look at the data box, they each have the same format.
• 03:20 First element is the step name, second element is the total time for
• 03:24 that step, the third element is the value-added time for that step.
• 03:29 Fourth is the batch size, the fifth item is the first pass yield for that step,
• 03:35 and the sixth item is the number of people involved in doing the work at that step.
• 03:40 Notice that the first two steps, setup and cleanup, have no value-added time.
• 03:46 There is no customer value-added activity going on at that step.
• 03:51 That doesn't mean that you don't do that step, it just
• 03:54 means that that step does not increase the value of the item being produced.
• 03:59 The next two steps have very low value-added time as compared
• 04:03 to the total time.
• 04:05 Well, the reason for that is the batch size.
• 04:07 While one item is being etched for 2 minutes,
• 04:10 the other 49 items are sitting idle.
• 04:13 Below the data box is another diagram called a time ladder.
• 04:17 The time ladder shows the allocation of all the process time into one of two
• 04:22 categories, either it's value-added time or non-value-added time.
• 04:27 There are no other choices.
• 04:29 The value-added time is the time spent in the process when the operator or equipment
• 04:35 is actively working on one item in a way that adds customer value to that item.
• 04:41 Everything else in that step is non-value added.
• 04:44 We can see this time playing out on the time ladder.
• 04:47 Since the first two steps have no value-added time,
• 04:50 all of that step time is on the upper rung of the ladder.
• 04:53 And the next two steps, the value-added time for one unit is on
• 04:57 the lower rung of the ladder, and all the rest on the upper rung.
• 05:01 So this shows the amount of value-added time for
• 05:05 one item to go through this simple process.
• 05:08 A caution, not only is it important to have the same elements in each data box,
• 05:13 but make sure that everyone is collecting data using the same definition of
• 05:18 the data element.
• 05:19 That means the same units should be measured in the same way.
• 05:22 If possible when collecting data, try to measure
• 05:25 a number of items going through that step and then use the average value.
• 05:30 If you just follow one item, it's likely that that item will be treated special,
• 05:35 and you won't get a good picture of what is normally happening in the process.
• 05:39 In many organizations today, some aspects of a step may be recorded in
• 05:44 an information management system, such as an ERP or CRM system.
• 05:48 When that happens, you have a timestamp for that step, and you can use that when
• 05:53 looking at historic records to determine the average amount of time for
• 05:57 each item to go through the process.
• 05:59 I recently worked with an organization, where we did not have a timestamp for
• 06:04 their system for every single step, but we did have a timestamp for
• 06:08 about half of them.
• 06:09 With that, we could create a pretty accurate time ladder.
• 06:12 We just had to determine how to allocate the time across several
• 06:17 steps that occurred between the time steps.
• 06:20 >> When some Black Belts and Green Belts think of data,
• 06:23 they only think of Six Sigma statistics.
• 06:25 But lean analysis is also heavily dependent upon collecting and
• 06:30 analyzing data.

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