Value Stream Map Data Box

Quick reference

• 00:05 Hello, I'm Ray Sheen.
• 00:06 Your Value String Maps are also characterized
• 00:09 by the Value Stream Data Box that is associated with each step.
• 00:12 Let's take a closer look.
• 00:14 A data box is just that,
• 00:16 a set of boxes on your value stream map that encloses the data.
• 00:20 Every step will have a data box located just below the step.
• 00:25 Each data box contains the measurable data that is associated with that step.
• 00:30 Now to make it easy to read the map, every data box on a map
• 00:34 will have the same list of data in the same sequence in the box.
• 00:39 Which data items are listed change from map to map, but
• 00:42 the data items are consistent within a Value Stream Map.
• 00:47 Now normally, they will have at least one time-based data element
• 00:51 such as total time or value-added time.
• 00:54 Normally, there will be at least one resource-based element
• 00:57 such as the number of people or units of equipment in that step.
• 01:00 And normally,
• 01:01 there will be at least one quality based element such as first pass yield.
• 01:05 In my experience,
• 01:06 most data boxes will actually have three to eight data elements.
• 01:11 Your business may have a standard data box format.
• 01:14 And if so, use it.
• 01:16 If not, work with the organizations black belts to
• 01:19 decide what are the appropriate elements for your process.
• 01:22 Again, try to have time, resource, and quality elements in your data box.
• 01:28 Another data recording approach found on many Value Stream Maps is the time ladder.
• 01:33 The time ladder shows the allocation of all process time into one of two
• 01:37 categories, either it's value added time or non-value added time.
• 01:41 There are no other choices.
• 01:44 The value added time is the time spent in the process when the operator or
• 01:48 equipment is actively working on the process item in a way that adds customer
• 01:53 value to that item.
• 01:55 Everything else is none value added.
• 01:57 That means if the non-value added time includes all the time spent by items in
• 02:02 a batch that are waiting their turn.
• 02:04 It includes time when the item is sitting waiting to be worked on like on night
• 02:09 time or on weekends.
• 02:10 It includes when someone is working with that item but
• 02:13 their activity is not value added.
• 02:16 Things like moving the item from station to station or correcting an error.
• 02:20 When determining the values to use in the time ladder, use the average value for
• 02:24 the items that you're measuring, not the worse case or the best case.
• 02:28 Time ladder is normally shown below the data boxes on the value stream map.
• 02:33 The ladder is drawn as a set of horizontal lines with the lower ranks are the values
• 02:38 added time for each step and centered under the data boxes for that step.
• 02:42 And the upper ranks are the non-value added time between the steps.
• 02:47 So let's look at how all these come together.
• 02:49 As you can see, I'm showing four steps on a Value Stream Map.
• 02:53 Under each of these steps is the data box and below that data box is a time ladder.
• 02:59 When you look at the data boxes, they each have the same format.
• 03:02 The first element is the step name, second element is the total time for
• 03:06 that step, third item is the value-added time for the step,
• 03:10 fourth item is the batch size, fifth item is the first pass yield for that step,
• 03:15 and the sixth item is the number of people involved in doing the work at that step.
• 03:20 Notice that the first two steps, setup and cleaning, have no value-added time.
• 03:24 There's no customer value-added activity going on at that step.
• 03:28 Now that doesn't mean that you don't do the step.
• 03:30 It just means that the step does not increase the value of the item.
• 03:34 The next two steps have very low value-added time
• 03:37 as compared to the total time.
• 03:39 The reason for that is the batch size.
• 03:41 While one item is being etched for two minutes, the other 49 are sitting idle.
• 03:47 We can see this time playing out on the time ladder.
• 03:50 Since the first two steps have no value added time,
• 03:53 all of the step time is on the upper rung of the ladder.
• 03:56 In the next two steps,
• 03:57 the value added time for one unit is in the lower rung of the ladder.
• 04:01 And the rest of the time is on the upper non-value added run of the ladder.
• 04:06 So this is showing the amount of value added time for
• 04:10 one item to go through the process.
• 04:13 Caution, not only is it important to have the same element in each data box but
• 04:18 make sure that everyone who collects the data is using the same definitions of
• 04:22 the data elements.
• 04:23 Now that means the same units and measure the same way.
• 04:27 If possible when collecting data try to measure a number of items through a step
• 04:31 and use the average.
• 04:33 If you just follow one item, it is likely that item will be treated special and
• 04:37 you won't get a good picture of what is actually happening in the process.
• 04:41 In many organizations today, some aspect of a step may be recorded
• 04:45 in an information management system such as an ERP or a CRM system.
• 04:50 When that happens, you have a time stamp for that step.
• 04:52 And you can then look at historical records and
• 04:55 determine the average amount of time for an item to go through the process.
• 04:59 I recently worked with an organization where we didn't have a timestamp for
• 05:03 their system for every step.
• 05:05 But we did have a timestamp for about half of them.
• 05:07 We could then create a pretty accurate time ladder.
• 05:10 We just had to determine how to allocate the time across several steps
• 05:14 that occurred between two timestamps.
• 05:16 When some black bets and green belts think of data,
• 05:20 they only think of six sigma statistics.
• 05:23 But lean analysis is also heavily dependent upon collecting and
• 05:27 analyzing data.

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