The Plan-Do-Study-Act cycle lies at the heart of lean thinking. It arose from a need to systematically solve problems and make sure that once solved they would not arise again. I.e. PDSA is a way to make a system wide improvement.
Rooted in the scientific method, PDSA acknowledges that adults learn best by doing, and thus it encourages experimentation. The cycle is simple enough: we plan some work (which is actually a hypothesis); we do some work (run the experiment); we study the results (where we learn about the system we are experimenting against); and finally we take actions, making sure, for example, that if we’ve improved the system, we do not regress to a previous, dysfunctional state.
PDSA, because it deals in system wide improvements, is as concerned with root-causes as it is with their symptoms. An example, from the world of finance, might help.
Imagine an Accounting and Reporting department (or a similar department) within a bank. One of the accountants sees a problem with a number, tracks it back to a particular set of data within a spreadsheet, and then adds a quality check. This quality check is not a long term solution but rather a counter-measure that will enable the accountant to do their job.
Many companies stop at counter-measures, and in fact many companies have become experts at counter-measures (many companies wear this like a badge of honour, saying that they are great fire fighters). PDSA, however, asks for some much more rigorous thinking. Within a lean finance system our accountant would be asking some difficult questions:
- Why was the data corrupted in the first place?
- Who provided this data and how was it pre and/or post processed?
- If the person responsible for the data is under qualified, why? Who hired him or her? Should we change the way we hire?
- Did the data come from an external party? If so, which one?
This set of questions immediately does two things. To get answers to these questions, the accountant asking them has to cross organisational barriers. If the accountant can get answers, and implement a true fix, he or she will not only fix the data but make a system wide improvement.
Role Fixation, The Enemy Within
The example above clearly casts the role of accountant in a new light. Within the lean finance system, we see the accountant’s responsibilities extend to problem solving. And in fact, this is a specific example of a general truth. Within a lean finance system:
- The managers need to be problem mentors, guiding the problem solving process.
- The accountants need to be problem solvers.
- The business controllers need to be problem solvers.
- I.e. everyone has to become a problem solver.
Because lean asks for system wide improvements, lean initiatives can stutter because of role fixation, which limits the problem solver to their team. So, in the above example, a traditional system of finance, with its role fixation, would reward the accountant who added a quality check to his or her data. I.e. a traditional system of finance encourages counter-measures but not system wide improvements.
PDSA is a Way of Thinking
A lean finance system tells financial institutions to encourage inter-team work, it encourages, in a positive way, problem solvers to ‘stick their noses’ into other team's business. In doing this, it asks for a culture of transparency. This is why PDSA is not a set of tools but a way of thinking, a way of managing.
Can’t We Just Use the Lean Tools?
This is a question that gets asked often. My answer is always the same. You can do what you like, but don’t expect significant changes without a significant change in the way you think; a focus on tools moves the focus away from people, problem solving and dysfunctional ways of thinking.
An example may help here, too. Two years ago we heard about a financial institution that ‘went lean’. They introduced the PDSA cycle, they visualised workflow, etc. When I inquired if there had been a change in results, the answer I got was ‘no’. This is what happened:
- The 12 month plans that the company previously had were broken up and carried out as 12 one month PDSA cycles.
- The to-do lists that were previously stored in a spreadsheet were transferred to a signal board.
I.e. the company only changed the mechanism for writing down and talking about their plans. Had they really expected a radical improvement in system performance without a radical improvement in thinking? My colleague was at client last year. He told me that some teams has ‘gone lean’ but were just biding their time until the consultants left so they could return to their previous system of planning.
Why Do We Keep Get This Wrong? A Problem of Perception
In their book, Sobek II and Smalley say:
We want to get the problem taken care of and move on. At Toyota, however, the process by which the results are achieved is equally – if not more – important, and the ultimate goal is not just a problem resolved in the immediate term, but also that 1) the problem is less likely to occur in the future because the overall system is improved, and 2) the problem-solver has enhanced his or her problem-solving skills and is prepared to tackle even more challenging tasks in the future. This difference in perspectives fundamentally alters the way we see PDCA[*].
(2008, Sobek II and Smalley, Understanding A3 Thinking, Productivity Press, p. 4-5)
* PDCA stands for Plan-Do-Check-Act, which is another name for PDSA.
Many managers have heard of PDSA, but many, wrongly, assume it to be a planning tool, or a quality improvement tool, or a way to structure work. They do not realise that it asks that they become expert problems solvers, that it asks that they become coaches, and nor do they realise that it asks them to re-design their organisations to allow for inter-team cooperation. This perception of PDSA is why lean initiatives so often fail.
We Are Only Using the Tools, What Shall We Do?
I have seen a number of lean initiatives bootstrapped in a number of ways. Lean tooling can lead the curious to the lean literature. The lean literature is consistent, saying that lean is a way of thinking whose overriding structure is the PDSA cycle. Quickly these curious souls start to change how they perceive lean. From their change in thinking comes a set of new principles, and from these principles come structures. For example, a company I am helping have started to have coffee mornings that involve all departments. They have also started to train everyone in empathic listening. The reason for this is simple: to be good at cross-team problem solving you have to be good at cross-team communication. Empathic listening, with it’s focus on needs and the creation of win-win situations, is a good tool for my client to have in their lean box.
I personally think that mental models are important, and they need to be challenged, and that can best be done with a system of coaching. However, when rolling out a lean system of finance, a multi-facetted approach works well. Why not teach empathic listening at the same time as introducing the PDSA cycle? My answer, then, to those who started with tools is this: it’s OK to start with tools, just don’t neglect how you think.
One may perceive a book to be a great door-stop, but one would get more value from it by reading it (depending on the book, of course). It’s the same with PDSA; how we perceive the PDSA cycle will very much dictate how much value we derive from it. It’s not enough to start working in cycles and hope that everything else will fall into place. It will not. Real change in results are always precipitated by real changes in thinking.
This introduction to the scientific method includes a good visualisation. Harris, William, 'How the Scientific Method Works, available from: http://science.howstuffworks.com/innovation/scientific-experiments/scientific-method6.htm, accessed on 10th of May, 2013.