Are you familiar with the “five focusing steps”? This approach is at the heart of the Theory of Constraints (TOC), the school of thought initiated by Dr. Eli Goldratt, author of the bestseller The Goal.
The “Five Focusing Steps” are a counterpart to Deming’s PDCA – Plan Do Check Act: they are five steps for driving the improvement process. In this case, the idea is to consider a complete system – for example, the manufacturing flows in a factory – and focus on the critical steps or resources to improve the system as a whole.
TOC covers a broad field of application and is rich in concepts: the neophyte can quickly get lost and encounter difficulties in translating concepts into practical actions. In Intuiflow’s workshop management tools, we have developed solutions to make this approach easy to implement and sustainable. Let’s take a look:
1. Identify the Constraint
This step involves system constraint identification. Take, for example, a set of production flows in a workshop. What is the constraint, or what are the constraints?
It’s not always easy to see the constraint, especially in a “job shop” environment, where technological resources are shared by several routings. This identification of the constraint can be blurred by cognitive biases and divergent opinions. I recall a sheet-metal workshop where everyone was focused on welding operations. However, a slower, less noticeable manufacturing stage was actually the bottleneck, preventing on-time delivery.
To actualize constraint identification in Intuiflow, we use two key tools: the system load graph and process mining analysis.
System Load Graph
We start by defining the opening times and efficiencies of each work center to parameterize their capacity, calibrated to the demonstrated capacity.
We run the scheduling/load calculation at infinite capacity and summarize the load/capacity ratio over a given time horizon, say the next eight weeks, in the form of a system load graph.
This graph shows us, at infinite capacity, which resources are overloaded. One by one, we define these resources as constraints and run finite capacity scheduling on these constraints.
In a few iterations, we realize that by finite capacity controlling three of the workshop’s resources, we can effectively control most of the workshop’s manufacturing flows. These are likely the three resources to be constrained.
Process Mining Analysis
The second key tool we implement is process mining analysis. This analysis is based on transaction histories for routing operations, such as production orders over the last twelve months.
Through process mining, we visualize the flow lines (similar to a VSM) and see the queues we’ve experienced in recent months. A queue often forms before a constraint, creating a traffic jam before the bottleneck.
The graph below illustrates this type of analysis. Beyond identifying queues, this approach helps measure variability. An average queue of five days can reveal that some orders pass in a few hours while others take weeks, signaling a lack of control and proper management processes.
With these two tools incorporated into Intuiflow—system load graph and process mining analysis—we can quickly identify likely constraints. Of course, this approach requires discussions with operational staff to validate the relevance of the constraints, but it doesn’t take long to get all stakeholders to agree based on factual data.
We are now ready to move on to “2 – Exploit” in a future episode of this blog. Stay tuned.
Coming Next:
- Exploit
- Subordinate
- Elevate
- Repeat
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