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Problem Improvement

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About this lesson

Problem-solving often requires an interim solution while a permanent solution is being developed and validated. When multiple possible solutions are available, the team should recommend a solution approach.

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Problem Improvement

When to use

Determining the solution approach is the first step in the Improve phase of the Lean Six Sigma project. Depending upon the nature of the problem, an interim solution may be needed in addition to a permanent solution. Also, there may be multiple possible solutions and the team must decide on the solution path that will be followed.

Instructions

When determining a solution approach for a Lean Six Sigma project, there are three key questions that must be answered.

Interim – Permanent

The first question concerns the need for an interim solution. Based on the urgency or severity of the problem, some problems will require an interim solution. This interim solution is normally focused on addressing the immediate problem. It will isolate and quarantine the immediate problem, possibly conducting a recall of released items. These will need to be repaired or replaced.

While this addresses the immediate issue, it does not prevent the problem from recurring. A permanent preventive solution is needed to do that. When the permanent solution is put in place, elements of the interim solution – such as special screening tests – should be removed. If the problem is relatively minor or the impact is one that the business and customers are already attuned to, an interim solution will not be required and the team should immediately start working on the permanent solution.

Solution Path

Depending upon the nature of the problem and potential solutions, there are three solution paths open to the Lean Six Sigma team.

Single viable solution – When there is only one viable solution to the problem, don’t agonize over it, just implement it.

Mutually exclusive solutions – Multiple solutions are possible, but once a path is chosen, the other alternatives are no longer viable. In this case, evaluate all the options for both technical efficacy and the ability of the organization to implement the solution. Select the best solution and reject the others.

Multiple complementary solutions – Multiple solutions are possible and they can be implemented independently of each other. Each solution provides some benefit and in combination, they are even stronger than by themselves. In this case, prioritize the solution based upon their cost and impact and implement as many as the organization can afford, or until the project performance goals have been reached.

Solution Selection Matrix

To prioritize or select a solution among solution options as described in paths 2 and 3 above, a tool is needed to support the analysis. The solution selection matrix is the most commonly used tool. This matrix has many variations and names, but all of these variations follow the same general approach. A set of criteria for evaluating the options are selected – normally by the stakeholders. These criteria may also be weighted based on which is most important to the stakeholders. I prefer to use a weighting scale of 1-5 where 5 is for criteria that are critical to success and 1 is for nice to have, but not essential.

Each of the solutions is evaluated using a simple numerical scale. I prefer the scale of 1 to 9 but there are many scales in use. The option that fully meets or exceeds the expectations of the criteria is scored a 9 and the option that badly misses is a 1. Once each solution option has been scored against each criterion, the scores are multiplied by the weighting factors, and a composite solution score is calculated by summing the criteria scores. The solution with the highest score is the best solution option. In the example below, Solution B has the best technical performance, but Solution A has the best overall score because it's faster to implement, least expensive, and is aligned with the organization’s strategic goals.

Solution Approach	Factor	Technical Performance	Org Goal Alignment	Cost to Implement	Time to Implement	Total Score
Solution Approach	Weight	5	4	2	3	Total Score
Solution A		6	9	7	8	104
Solution B		8	5	3	4	78
Solution C		4	6	5	5	69

Hints & tips

You may need to initiate an interim solution before you have completed the Measure or Analyze phases. This is often needed if there is a health or safety risk to the problem.
If you have to follow solution path 2 – choosing between mutually exclusive options – engage your stakeholders in the decision process.
The weights for the decision criteria in the solution selection matrix should be established by the stakeholders, not the project team. The stakeholders will have to live with the result, the project is disbanded or goes on to the next project.
There are lots of different weighting scales and scoring scales. In virtually every case they will give you the same ranking of solutions, so don’t agonize over the scales. Pick one, or use the one you are directed to use and do the matrix.
The solution selection matrix is not so precise that differences in the solution scores of a few percent are not significant. If in the example above, Solution A scored 104 and Solution B was 101, I would say that as far as this analysis is concerned, their scores are equal.

00:05 Hi, I'm Ray Sheen.
00:06 It's finally time to move into the improvement stage,
00:10 this is what we've been building up to.
00:13 The purpose of the Lean Six Sigma project was to improve a product or process.
00:18 In this module, I want to highlight some of the key aspects and
00:22 how to approach this improvement stage.
00:27 >> Let's talk about what it means to solve a problem.
00:29 We can solve it in two ways and often need to do both.
00:33 We can take an interim corrective action to solve the problem by containing
00:36 the current issue and responding to the issue created for
00:39 the customer of the product or process.
00:41 This approach resolves the one instance by making it all better.
00:45 To do this, we isolate the problem to keep it from spreading,
00:49 which may mean that we need to do a recall or purge of previously completed items.
00:54 We then fix that problem for those customers who have been impacted.
00:57 That may include doing a repair, or restore, or
01:00 replacement of the item that was previously received.
01:03 This interim corrective action is a backwards looking
01:06 approach to fixing the problem we already have, but
01:08 does nothing to prevent the problem from reoccurring.
01:12 So we also need to do a permanent corrective action to complement
01:15 the interim corrective action.
01:17 This involves changing the product, process, or process control so
01:21 that the likelihood of the same problem happening is reduced.
01:25 Changing the product or process involves changing the six M's, material, manpower,
01:30 methods, machines, measurements, or mother nature.
01:33 It may often mean, changing how we control the product or
01:36 process using things like visual control or statistical process control.
01:41 For this permanent corrective action to be effective, it must be fully implemented
01:45 including the systems and the procedures that are affected.
01:48 One caution, once the permanent solution is in place,
01:51 you need to remove the interim solution elements that were adding cost and
01:55 complexity to the product or process.
01:58 Things like extra tests or inspections, or any re-steps.
02:02 I want to focus in now on some attributes of a good permanent solution.
02:06 For starters, a good permanent solution will normally need to include more than
02:10 just a technical solution to the problem, but
02:13 will often need to change the culture or environment also.
02:16 Some questions to ask are,
02:18 does the solution meet the standard desired performance, meaning does it work?
02:22 What are the impact of the solutions on other performance parameters?
02:26 Meaning, does it make anything else better or worse?
02:29 Do the individual and organizations involved accept the solutions as a viable
02:33 change, meaning, will they resist the implementation of the solution?
02:37 Does the organization have time and
02:39 resources available to implement the solution?
02:42 Meaning, can we afford it?
02:44 The answers to these questions will help you to determine if the solution
02:47 is viable.
02:48 And of course, the permanent solution must take into consideration what has been done
02:52 for the interim solution.
02:54 The interim solution put a band-aid on the wound.
02:57 The permanent solution must heal the patient and
02:59 remove the band-aid without reopening the wound.
03:03 As we start to develop a product or process improvement,
03:05 we often find that there are several ways we can proceed.
03:09 We need to select a good approach.
03:10 In order to make a wise selection,
03:12 there are several different ways to approach the selection process.
03:17 The easiest way to decide what to do is when there's only one option that is
03:20 available.
03:21 In that case, the only decision is when to implement the path is known.
03:26 A good rule of thumb when fixing a problem is to implement it as soon as possible.
03:30 Sometimes the decision is between two incompatible approaches.
03:35 Once you've selected one approach, you can't implement the other also,
03:38 is an either or proposition.
03:40 If I decide to install a new computer system to run the equipment,
03:44 I won't also repair and rebuild the old equipment, it's one or the other.
03:49 When faced with this kind of choice, evaluate the options and pick the one that
03:53 is best overall, not just technically, but the one that is good technically,
03:57 implementable, affordable, and will be accepted by the stakeholders.
04:01 The third type of decision is when there are multiple complementary options.
04:06 It is not an either-or proposition, but it is a both-and proposition.
04:11 I can replace the system, and improve the lighting, and
04:14 add graphics to the work instructions, and provide training to the operators.
04:19 And, and, now the question is, how many of these can we afford to do and
04:23 which ones to do first?
04:26 In this case,
04:27 I normally rank order solutions by effectiveness of fixing the problem and
04:31 then start to implement them from the top of the list going down, until I run out
04:35 of money, or I've met and exceeded the stakeholders expectation on performance.
04:40 The second and third points required a selection process to evaluate or
04:44 prioritize the solution options.
04:47 Let's take a moment to consider the most commonly used
04:50 approach the selection matrix.
04:51 There are many different flavors and names for this matrix, but
04:54 they all follow the same general approach.
04:57 Each option is scored on a variety of criteria and
04:59 the options with the best overall score is the one selected or prioritized first.
05:05 Now, the criteria used, both the number and the specific items, are typically
05:09 based upon the constraints on the team and the objectives of the stakeholders.
05:13 These vary with every project,
05:15 many organizations will also weight the criteria based upon their importance.
05:20 This weighting should be derived by stakeholders not team members to ensure
05:24 that they have buy in for the implementation.
05:27 There are lots of different weighting scales, I prefer the 1 to 5 scale,
05:31 where 5 is essential for success and 1 is just kind of nice to have.
05:36 In this scale, you can have multiple criteria with the same weight.
05:39 There are other slightly different scales, but
05:41 they all work essentially the same way.
05:43 I recommend you use the one most commonly used in your organization.
05:48 Each solution is then scored with respect to the criteria.
05:51 I like to use the 1 to 9 score, but I've seen 1 to 5, 1 to 7, and 1 to 10.
05:56 Again, use whatever is common for your organization.
06:00 When doing the evaluation, the high number indicates that the solution is excellent
06:04 with respect to that criteria, and
06:06 the low number means that it does not address it very well at all.
06:10 Now, multiply the weighting factor times the criteria score and
06:13 add up each row to find the total weighted score for each solution.
06:17 The one with the highest score is the best or highest priority solution,
06:21 there's one final topic to mention as part of the problem solving process, and
06:25 that is testing or verification that the solution works.
06:29 You should always test your solution before implementation.
06:32 Here's some aspects of the testing program.
06:35 Of course, one of them is to test that the solution x actually fixes the problem.
06:39 It either prevents or controls the underlying root cause.
06:43 In addition, test to ensure that the solution does not create a new harms or
06:47 hazards, or quality problem in other parts of the process.
06:51 Verify that the new process change is implemented and is both capable and
06:54 stable, and that may require some statistical testing.
06:58 Verify that the management systems that support the solution have been changed and
07:02 are operational, that way, they reinforced the changed approach and
07:06 did not pull the process or operators back to the old problem.
07:10 Verify that any unnecessary artifacts of the original temporary solution have been
07:14 removed and replaced with the new permanent solution.
07:19 >> Problem solving is more than just a quick fix.
07:22 There are interim and permanent solutions to consider,
07:25 and both technical and organizational factors that must be weighed.

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Problem Improvement

About this lesson

Exercise files

Quick reference

Problem Improvement

When to use

Instructions

Interim – Permanent

Solution Path

Solution Selection Matrix

Hints & tips