The word ‘Flow’ has a few differing meanings, but all imply the smooth transition from one place to another.
To improve operational efficiency, as well as the productivity of a process, the best way to go about it is to remove the sources of interruption to the smooth flow of the product or service from one point to another.
In some cases, the results of the interruption will be obvious, a build-up of WIP waiting for the opportunity to move forward, and its sibling, lack of product to move into a waiting machine, or part of a process. In others, it will not be so obvious, and often takes time to isolate and address.
Fortunately, the metrics of ‘Flow’ are simple, there are only two:
Throughput.
Cycle time.
How much moves from one point to the next, and how long does it take.
These metrics can be applied to a whole process, and parts of the process. Usually an improvement starts with the former, and as investigation proceeds, it digs into individual stages in the process, removing interruptions progressively, starting with the biggest, which may in itself have several components.
Tracking and making transparent these two measures, while having those involved take responsibility for continuous improvement is where the productivity gold lies hidden.
Tracking can be achieved by some sort of digital visual display, now everywhere, and/or the original and perhaps still best way, with Kanban cards (which means in Japanese ‘visual signal’) that follow the process, step by step. Utilising both achieves the benefit of both wide transparency, and individual responsibility.
In its simplest form, the metrics track time and delivery.
The example above in the header shows, in period 1, 8 units were delivered, period 2, 10 units, and so on.
The time will be whatever is appropriate to the process being measured, as will the units.
It may be minutes, days, weeks, whatever is appropriate.
This may represent the total process, or a small part of it. In the latter case, it will usually be sensible to add a column between each of the process stages to capture the WIP, the reduction of which is almost always the best place to start when optimising the flow through a multi stage process.
When you need an experienced head to assist you think your way through this seemingly simple idea, give me a call.
