by Kevin W. Posey
Have you ever felt the plant tour was a waste of time at the start of an audit? Adding aspects of the lean rapid plant assessment (RPA) tool to your audits can add significant value to plant tours and your audit reports. The lean RPA tool will allow you to maximize the return on a typical plant tour for audits where assessing lean, efficiency, or effectiveness is an important goal.
In this article I will cover a brief history and background of the lean RPA methodology. I will cover what it is and isn’t, the benefits, and how and why it can be used in appropriate audit situations. Finally, I will conclude with the details of the two assessment tools that make up lean RPA and how they are used.
Lean RPA was developed by Dr. R. Eugene Woodson in 1998 based on his learnings from the automotive industry in the early 80s. Dr. Woodson traces his experiences back to his time using the Toyota Production System to evaluate automotive suppliers. Dr. Woodson first published his concept in the Harvard Business Review in May 2002. From 1998 to 2002, Dr. Woodson—now a professor of operations management at the University of Michigan Business School—facilitated the use of the lean RPA method at least 400 times with more than 150 companies. Usage of lean RPA included multiple assessments taken by teams of assessors, allowing for statistical analysis of averages and standard deviations and also includes one company where lean RPA was repeated at a later date and showed how the company improved its score dramatically based on lean-focused continuous improvement.
Let’s get more specific and talk about what lean RPA is. One fundamental idea behind lean RPA is this: to a trained eye, even a quick plant tour can reveal a lot about a company. I sometimes call this Murphy ’s Law of auditing: whatever is going wrong in your plant, an auditor will be there exactly when it happens. The corollary, though should also be true: things that are going right in the plant will be going on when an auditor is there. Compliance-based auditing only focuses on Murphy’s Law and finding out where the nonconformances are and where the process noncompliances exist.
Lean RPA guides an auditor to also look for what is going well. Is there evidence of lean principles in action? Is there objective evidence of efficiency, effectiveness, or continual improvement? Are lean principles consistent throughout the factory, or only in pockets of best practices?
In lean terminology, we might refer to lean RPA as a “gemba walk,” that is focused by the audit purpose and the limited timeframe available. Key to the gemba walk is that the lean RPA must go to the place where things are happening. You can’t assess lean based on procedures and records alone.
Now that we’ve talked a bit about what lean RPA is, let’s consider what it isn’t. First, it is not a substitute for due diligence in an acquisition. Second, it is only one factor to consider when assessing a company—it’s not the whole picture. Finally, it’s not a complete lean assessment but a tool for rapid or initial assessment.
With these limitations in mind, why would we choose to use the lean RPA? The answer is quite simple: lean RPA is a simple and powerful tool to take visual cues about an operation’s strengths and weaknesses and rapidly assess the leanness of the operations. It can also help identify potential problems with suppliers early. When used internally, lean RPA can be a powerful tool to identify areas of efficiency and effectiveness that should be treated as best practices.
Now we know what lean RPA is and what it isn’. You may be wondering how it applies to audits. Or more directly, can it be used during plant tours for first- and second-party audits?
The answer is yes; it began its life as a supplier audit tool with Toyota, so there is good history for its use and applicability for auditing. In fact, lean RPA applies very well during plant tours for internal and supplier audits.
But wait just one moment… isn’t it important that we not take notes during the tour? Doesn’t note taking detract from picking up visual cues and impede communication with employees on the plant floor? Yes, at least based on the way I train and mentor auditors, so application of the tool in audits requires proper planning. Appropriate use means you need to have a plan for the tour, and a solid memory to record your notes after the tour.
The first key tool is the RPA rating sheet, which comprises 11 categories that are rated numerically to assess the leanness of the company. The numerical rankings are based on six pre-defined levels of performance. In figure 1 below, you can see the categories and rankings in an example of an RPA rating sheet template. The second key tool is the lean RPA questionnaire (figure 2) which includes 20 questions that the auditor provides simple “yes” or “no” answers to. These 20 questions will challenge the auditor to determine if the company uses best practices in each of the 11 categories from the lean RPA rating sheet. Each question may only be answered “yes” if the plant adheres to the lean principle implied by the question as supported by objective evidence.
These two tools are designed to work together by correlating items on one tool with the other. Specifically, as indicated in table 1, every category from the rating sheet has several questions on the questionnaire that correlate with it. The correlation helps ensure consistency across both rating tools. For example, if you rated customer satisfaction as poor but answered questions 1, 2, and 20 as yes, you have a potential error in your methodology.
|Lean RPA Rating Categories||Lean RPA Questionnaire questions|
|Customer Satisfaction||Questions 1,2,20|
|Safety, Environment, Cleanliness, and Order||Questions 3-5,20|
|Visual Management System Deployment||Questions 2,4,6-10,20|
|Scheduling System||Questions 11, 20|
|Space, Movement, and Flow||Questions 7,12,13,20|
|Inventory and WIP||Questions 7,11,20|
|Teamwork, Skills, and Motivation||Questions 6,9,14,15,20|
|Tooling and Equipment Condition/Maintenance||Questions 16,20|
|Management of Complexity and Variability||Questions 8,17,20|
|Supply Chain Integration||Questions 18,20|
|Quality System Deployment/Commitment||Questions 15,17,19,20|
Table 1: Correlation of Lean RPA Categories to Questions
Figure 1: Lean RPA Rating Sheet Template
Figure 2: Lean RPA Questionnaire Template
Now that you’ve seen both tools in the lean RPA workshop, you may be wondering if you need to use both tools. Ideally, yes you should. You would normally complete the figure 2 lean RPA questionnaire first and use it along with your observations from the tour to assess the more detailed numerical rating in figure 1. Use table 1 as your guide to apply the question results to the correct categories for rating.
I endorse the practice of reviewing figure 2 before a tour and then filling out the answers immediately after the tour without using figure 1. This highlights major areas of positive and negative with minimal time investment and without disrupting the tour or audit flow.
In Dr. Woodson’s intended implementation of lean RPA, an assessment group is selected and then trained to go in as a team to perform the assessment, with each member focusing in areas where he or she is a SME, similar to an audit team. A full lean RPA like this could easily involve three to five people with an entire day, or more. This may be perfect if you are doing due diligence for an acquisition or merger, but isn’t necessary if you’re using the methodology to get more value from our audit tours.
Now that we have completed the assessment and have some concrete results, what do we do next? In the fashion of any good KPI or metric, we start by considering where the rating sheet scores rank compared to maximum and minimum. The possible range of scores is 11 to 121, with a median of 55. With results in hand, we can certainly compare and benchmark Dr. Woodson’s results in his 2002 Harvard Business Review article, “Read a Plant—Fast.”
Overall, the results will indicate whether there is room for improvement or if the assessed factory is already running world-class lean processes. When there is room for improvement, the scores on the rating sheet are the roadmap for determining a course of focused improvement. Categories with low ratings are instantly visible opportunities for improvement and should be the first steps on a company’s journey to continuous improvement in lean processes. The best way to measure our progress or improvement is one or more follow up lean RPA visits. The RPA results can be one metric showing improvement in the company/factory’s advancement. A yearly assessment can be a powerful tool in a journey toward world-class lean operations.
Finally, to bring our lean RPA journey to a conclusion, let’s remind ourselves what was covered. We started with a brief history and background of the lean RPA methodology. We covered what it is and what it is not. We discussed the benefits of the lean RPA, and how and why it can be used in appropriate audit situations. Next, we went through the details of the two assessment tools that make up the lean RPA and discuss how they are used.
Hopefully you agree that adding aspects of the lean RPA to audits can add value to audit tours and reports, and that the lean RPA tool can maximize return on audit time spent during a plant tour, particularly where assessing for lean, efficiency, or effectiveness is an important goal.
About the author
Kevin Posey is a quality and regulatory executive consultant with international experience in quality management, product development, manufacturing, and regulatory approval for medical devices, defense and aerospace, mining and exploration, and industrial equipment and controls. He also consults, trains, writes, and speaks on quality management, auditing, innovation, and medical devices. His undergraduate degree is in aerospace engineering, to which he has added an MBA in international business. Posey is the education and training chair for the ASQ Audit Division, a founding member of the Innovation Interest Group, and an ASQ senior member, with certifications as a Quality Auditor, Biomedical Auditor, Manager of Quality and Operational Excellence, Quality Engineer, Software Quality Engineer, and Six Sigma Green Belt.