Lean Improvement: Flow

Quick reference

• 00:04 HI, I'm Ray Sheen.
• 00:06 Now let's turn our focus to improving the flow of the Lean process.
• 00:12 We talked during the measure stage About defining the as is process
• 00:16 now its time to create a should be process.
• 00:20 This is how we hope the process will operate
• 00:22 once all the changes are implemented.
• 00:24 The nice thing about lean improvements is that many of them are localized to just
• 00:28 a few steps.
• 00:29 And that means you can start to put them in place without needing to wait for
• 00:33 everything to go in at once.
• 00:34 So don't delay incorporating changes,
• 00:37 start getting benefits as soon as possible.
• 00:40 Some improvements will focus on flow and streamline the flow of the Value Stream.
• 00:45 I'll cover these in this module.
• 00:47 They help the process be faster, which often means lower cost and
• 00:50 more responsive to customer needs.
• 00:52 Some improvements will focus on improving quality at each step.
• 00:55 I will discuss techniques for those in the Pokeoke and the 5S modules.
• 01:00 Those improvements reduce cost, reduce uncertainty in delivery and performance,
• 01:05 which improves customer satisfaction.
• 01:07 And some improvements will focus on approving the process scheduling,
• 01:11 applying pool principles instead of push.
• 01:13 I will cover those in this module on schedule improvements,
• 01:17 these changes often give us a process that is faster, lower cost,
• 01:21 lower in the inventory, better quality, and more responsive to customer needs.
• 01:26 So let's look at the different categories of flow improvements.
• 01:29 You may not use all of these on every project, but
• 01:32 you are likely to use at least a few of them.
• 01:35 The focus of these is to reduce waste in the value string.
• 01:38 All the measurements and analysis so far, have been to find the waste, now it's time
• 01:43 to get rid of it, The most obvious, is to reduce the non-value added activities.
• 01:48 Try to eliminate these steps, or combine them to shrink them.
• 01:52 Another technique is to redesign the steps so that they fit within the TAKT time.
• 01:57 This may mean splitting some steps and
• 02:00 indicate an opportunity to combine others together.
• 02:03 If you can't get a step below the TAKT time.
• 02:05 You'll need to duplicate the workstation and all the resources so
• 02:09 that multiple units can be going through in parallel.
• 02:12 When I do that, I try to stagger the start of a unit at each workstation.
• 02:16 So that I will always have a unit completing at each TAKT time interval.
• 02:21 Another change is to reduce setup and changeover time so
• 02:24 that you can get to a batch size of 1.
• 02:26 I've been amazed at the benefits of this technique.
• 02:29 It leads to an immediate understanding of problem steps,
• 02:32 allowing further continuous improvement.
• 02:34 But more about that on the next slide.
• 02:37 Finally,apply the theory of constraints to prove total process cycle time by
• 02:41 eliminating bottlenecks.
• 02:43 Again more than that in a later slide in this module.
• 02:46 Let's talk about batch size of 1.
• 02:48 Batch size of 1 leads to huge reduction in cycle time and the level of.
• 02:53 I've seen processes routinely take weeks to accomplish.
• 02:57 Accelerate until they're only taking a few days.
• 03:00 In fact I had one manufacturing process that I was responsible for
• 03:04 go from a 2 week cycle time to a 5 hour cycle time.
• 03:07 That was of course faster and more responsive to urgent customer requests,
• 03:11 but we also found it less expensive because of less scrap.
• 03:15 We no longer had units being damaged as they were handled, and mishandled.
• 03:19 going into and out of temporary storage or holding containers.
• 03:23 The technique is self-explanatory, but there are several major implications so
• 03:27 this will work really well.
• 03:29 First, the process must be simple.
• 03:31 Think about the swim lane chart analysis.
• 03:33 I want to cross as few lanes as possible to reduce handling.
• 03:37 Also, if people or equipment are not dedicated to a particular product line or
• 03:41 an item type I need to make sure that the setup and change over time is very low.
• 03:46 Second, there's implication for process control.
• 03:49 Scheduling a tracking system must be real time or nearly so.
• 03:53 Otherwise, a preceding process step will keep slowing items to the next step.
• 03:58 And not now there's a problem in the existence of a bottleneck,
• 04:01 more about that when we discuss visual control in another module.
• 04:05 The last item I wanna talk about is constraint management,
• 04:09 this is based upon the theory of constraints developed by Dr.
• 04:12 Eilyahu Goldratt and made famous by his book The Goal.
• 04:15 The outlines of five step process for managing process constraints and
• 04:19 the first step is pretty obvious.
• 04:20 Identify the constraint.
• 04:22 This is the bottleneck and
• 04:23 if we can increase the flow through this point we speed up the entire process.
• 04:28 One of the easiest ways to do this is to watch for
• 04:31 where process items such as inventory start to stack up.
• 04:34 Something is constraining the flow.
• 04:36 Step 2 is to focus the constraint.
• 04:38 Make sure the constraint resources are focused doing the part of the process
• 04:43 that only those resources can do.
• 04:45 Offload non-essential or
• 04:47 generic activities to other resources With excess capacity.
• 04:51 Step 3.
• 04:52 Subordinate everything to the system's constraint, schedule all preceding
• 04:57 activities to provide a small surplus of improcess WIP at that point.
• 05:01 So, the constraints step is never able to get caught up.
• 05:05 Since their constraint step limits their total output from this process,
• 05:10 an idle constraint is lost process capacity.
• 05:12 Lost forever.
• 05:14 I know this is countered to some of the other lean improvement approaches, but
• 05:19 it's only a one step in the process and only for
• 05:21 a process that is capacity constrained.
• 05:24 Notice that so far after doing steps one, two and three, we've not hired any new
• 05:27 people or bought any new equipment We haven't spent any money.
• 05:31 Yet I have often seen a nearly 50% increase in process output by doing
• 05:35 those first three steps.
• 05:37 Well now it is time to spend money.
• 05:39 If the first three steps did not break the constraint,
• 05:42 add additional resources to increase the capacity of the constraint.
• 05:45 Add people or equipment to up the capacity.
• 05:49 Finally, once that step is no longer the constraint,
• 05:52 go to the next constraint and do the five steps again.
• 05:55 There is always a process constraint,
• 05:57 something limits how much the process can do.
• 06:00 Keep moving from constraint to constraint, until the capacity exceeds the demand.
• 06:06 When cycle time, cost, or flow are issues, apply these flow improvement
• 06:11 tools can significantly improve your process performance.

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