Transportation Lean Forum

TLF Toolkit

The TLF Toolkit collects resources, links, and targeted background information to help you get started and continue to advance your Lean practice. Each of the tabs below collects a category of Lean tools and resources or focuses on a aspect of Lean practice.

Plan Do Check Act (PDCA) in the 9-box A3

Though PDCA is the fundamental framework, the A3 form is used to convey the entirety of an improvement project. This is done for communication efficiency, so that anyone can get a clear summary of an entire project lifecycle in one view. A3 and PDCA are not at odds here, but rather, A3 is made up of PDCA cycles. See the following illustration in Figure 1.
PDCA in the 9 box a3
Figure 1: A3 and PDCA
Colors in Figure 1 are described by the key. The A3 format is given with each box colored according to the corresponding PDCA step. Three different cycles of PDCA are explicitly shown in the A3. Cycle 2 may be repeated until the problem no longer exists.

Cycle 1 contains the first iteration of PDCA, which represents the current state dilemma. The Reason for Improvement and Target State are a succinct PLAN of where we want to go and why it is important. The Initial State is the result of “DO-ing” the process that produced results somewhere short of the ideal. A Gap Analysis CHECKs the final outcomes of the initial state, the execution of the ideal process, and the appropriateness of the current process for achieving the final outcomes. Finally, we seek to determine the root causes of the problem, and determine where to ACT in executing a Possible Solution.

Cycle 2 involves the escalating process of an iterative scientific method. On the first pass through Cycle 2, the Possible Solution receives a small experimental PLAN is devised that seeks to attack the problem area as defined under Act of Cycle 1. Next, an isolated Rapid Experiment is “DO-ne”. A new Gap Analysis CHECKs if we have made a good improvement toward our goal, and a new root cause is determined. A string of small, Rapid Experiments are carried out (even if only theoretically as thought-exercises) in this cycle until an acceptable change is seen. There may be additional cycles necessary here, as small experiments are expanded to affect more and more people.

Cycle 3 is merely the final iteration of PDCA for the project. This is broken out in the A3 because it is also likely the only iteration that affects 99% of the problem area. For this reason, more work is done in implementation PLANning, DO-ing the final implementation, CHECK-ing through formal evaluation, and ACT-ing to provide potential fodder for the next project.
Now, for more details and tools related to each step in PDCA:


Discovering issues, problems, and potential solutions is part of the “Plan” step. The Plan step is about characterizing the current state, imagining a better future state, and charting a path to that future. In its simplest sense, this is accomplished by seeing a problem (banana peel on the sidewalk), coming up with a countermeasure (step over said banana peel), and laying out the details for execution (left, right, left, right, hop-left, right). In this frame of mind, everyone is constantly planning their next steps (literally) according to the PDCA Plan framework. Although this is a very simple concept, there are tools for completing this step:


Just as the proposed solution can take any form, there are few general tools to implementation. In everything, having a plan, clear delegation, and timelines will be helpful, but these should have been fully developed above. Also part of this step is the measurement and data collection from the experiment or implementation. The following tools for completing this include:


Now that all is said and done, and the results are in, we can analyze the results and check for three things:
• Have we now achieved “success” given our scale and scope?
• Was the plan executed correctly?
• Was the plan appropriate for the intended purpose? Tools that are helpful for analyzing results include:


With a clear picture of the results, we can now look for a root cause to the problem, the experimental/implementation plan, and the plan’s execution. These tools are appropriate for this step:


Another dimension to this Toolkit is the improvement scope, which is divided into three categories: Everyday Ideas, Local Lean, and Global Lean. You may have worked on improvement efforts in one or more of these categories. While their look and feel may be different, they actually use the same core process, PDCA. The main difference between them all is in the size and scope of the change that they seek to make.In general, Everyday Ideas are small, isolated changes that can be easily implemented with minimal investment by the person who came up with the original idea. Everyday ideas are the most important type of improvement for many reasons, summarized here. Everyday Ideas are not a glorified suggestion box. The differences are many. If an idea is too complex to implement with readily available resources and/or it will affect an entire work group, then a Local Lean project should be started. This effort will be much more highly structured, but it will have a much larger effect.If the idea proves too large even for the work-group or if it requires a significant amount of external resources to carry out, then a team should be formed to execute a Global Lean project. Although there are few structural difference between Global and Local Lean projects, Global projects will often have top management sponsorship and significant change management components.