Control Plan

Quick reference

• 00:05 Hi I'm Ray Sheen and it's no surprise that during the control phase for
• 00:09 project we will need to create a control plan.
• 00:12 Let's take a look at the elements of a control plan.
• 00:16 I'll start by considering the control strategies based upon your process
• 00:20 performance.
• 00:21 There're four different strategies that you could pursue.
• 00:24 These strategies are based upon the typical performance of your process.
• 00:27 It could be in statistical control,
• 00:29 meaning there are no special cause variation, only common cause.
• 00:33 Or it could be out of statistical control,
• 00:35 meaning there is the presence of special cause variation.
• 00:38 Second, your process may have been producing conforming parts and
• 00:42 items or it could be creating errors.
• 00:45 Now it should be no surprise that our goal is to have a process that is in
• 00:49 statistical control and always producing conforming items. That is the ideal state.
• 00:53 We should strive to do design a solution that gets us there and
• 00:57 then put in place a control plan to stay there.
• 01:00 Sometimes the process is in control, but there are some nonconfirming results.
• 01:05 This is a process capability issue.
• 01:08 The specification limits are tighter,
• 01:10 than what the process is able to consistently achieve.
• 01:13 We called this threshold performance,
• 01:15 because we're on a threshold to being able to get to ideal state or
• 01:18 we're also on a threshold of having a large amount of a defects.
• 01:21 From a control strategy standpoint, we want to maintain control, and
• 01:25 be constantly monitoring for the instance where the result is nonconforming so
• 01:30 that it can be reworked.
• 01:32 This is also a candidate for a further Lean Six Sigma project.
• 01:35 The third strategy is for the case where the process is out of control and
• 01:39 routinely producing nonconforming results.
• 01:42 In this case, the process is broken and typically,
• 01:45 everyone knows this. There are ongoing problems and chaos is evident at times.
• 01:49 You should not be in this state at the end of a Lane Six Sigma project.
• 01:54 Although, this is often the case at the beginning of the project.
• 01:57 If your team is still in this condition, your project is not yet over.
• 02:01 The fourth condition is actually the most dangerous.
• 02:04 The process is not in control, but it is producing conforming results.
• 02:08 That means that some special cause is overriding normal process performance to
• 02:12 ensure that the result is conforming,
• 02:14 this condition can lead to a false sense of security.
• 02:17 It's also difficult to create a control plan for this condition because
• 02:20 the process does not have the inherent ability to control what is happening.
• 02:25 It is the special cause that is overriding everything, and
• 02:28 as soon as the special cause changes, the results will likely be disastrous.
• 02:33 So let's look at the control plan.
• 02:35 The control plan is a set of activities performed by the process operators,
• 02:39 equipment, or supervisors that will maintain the process performance at
• 02:43 acceptable levels of customer satisfaction.
• 02:46 Without a control plan, the process improvement often fades away, and
• 02:49 the process reverts back to what had been happening originally.
• 02:53 On top of that, the Control Plan should be generating and monitoring
• 02:57 the process performance data which can provide insight into further improvements.
• 03:00 It should immediately note the introduction of special cause variation,
• 03:04 so that they can be controlled and prevented.
• 03:07 When I build a Control Plan, I build it with three components.
• 03:11 The documentation, it must be there for others to reference, the monitoring plan,
• 03:15 what we are watching for and what we should expect, and
• 03:18 then finally, the response plan.
• 03:21 When something different than expected happens, what should be done?
• 03:25 Here's an example of a very simple template that I've used.
• 03:29 The first two columns are the documentation.
• 03:31 This is the process step, and what are the procedures, work instructions or
• 03:36 checklists that instructors and operators use to accomplish that step.
• 03:40 If we don't document it, we can't expect it to stay under control.
• 03:44 The next three columns are for monitoring.
• 03:46 This is what is being measured, how it is being measured, and how it is recorded.
• 03:50 Now you don't have to have a measurement for every step, but
• 03:54 every critical process output should be measured at some point.
• 03:58 And some steps such as an inspection or
• 04:00 a test step in the process are strictly measurement steps.
• 04:04 The last few columns are the Response Plan, and I'm showing one, for
• 04:07 what to do if a measurement is out of the allowed range, another call for
• 04:11 highlighting preventive actions that can be done with this step.
• 04:14 The response plan strategies are so important,
• 04:17 that we'll spend an entire module on them here in a few minutes, but
• 04:21 let's wrap this up with a few more comments about monitoring.
• 04:25 As part of the measurement aspect to the monitoring plan, each process output
• 04:29 should be identified at the appropriate step, and the target performance,
• 04:33 along with the allowable tolerances and specifications, should be included.
• 04:38 And where it's appropriate, the monitoring plan should also include
• 04:41 a targeted tolerances for the process inputs.
• 04:44 In many cases it's the control of the inputs
• 04:47 that will screen out special cause variation effects.
• 04:50 Finally, they could clear the Monitoring Plan how the measurement is taken,
• 04:54 who takes the measurement and where this recorded.
• 04:57 Is it going on a run chart or control chart.
• 05:00 It is going in a database that automatically tracks and flags problems.
• 05:04 The point here is that monitoring implies someone or
• 05:06 something is actually checking the data to be sure it's acceptable.
• 05:10 We don't just record in order to have an activity to do.
• 05:14 We record it to be able to conduct realtime tracking of the process.
• 05:20 We aren't trying to be control freaks, but experience tells us that if we don't
• 05:25 change the way we control the process, any improvement will soon slip away.

Lesson notes are only available for subscribers.