What The Flow (WTF)?
Going with the flow?
Every year, Ghent hosts the so-called Midwinter Night Run. Möbius is a loyal participant in this event. It is very popular, which explains the great mass of people trying to find their way through the city. My colleague Peter had been running it for some years and clearly understood the importance of flow. While we all obediently joined the back of the queue, Peter, using some subtle stretching manoeuvres, managed to get a place at the front.
If you have already participated in this kind of event in a city, then you will know that running certain parts of the course is not that simple. Everyone leaves the starting block together and as soon as you hit a little bridge or narrow street, you get stuck. The masses all need to cross the bridge or get through the narrow lane, but can’t all get through at once and this means that they are kept waiting. Running at the front, Peter did not encounter this problem. And although it didn’t exactly make him Mr Popular, he did achieve a far better time than ours (and not only because he can run faster).
It’s exactly the same effect when you allow a gigantic batch of products or customers to run through a process. Longer waiting times occur at bottlenecks, at the parts of the ‘course’ requiring more time.
How can you, as an organization, ensure that you make good time?
1. Build a valuable course: Run through the process with your product or customer and see how long each step takes, where time is lost, and where the product or client is kept waiting. Does each step add value? – Useful tools in this matter are a travel sheet or value stream mapping. In this way, we were able to reduce the flow time for a district construction request from 6 weeks down to just 4, based on a “critical analysis of the critical path”.
2. Get rid of diversions: While walking the course, consider whether it is a logical path or whether parts of the path are just “diversions” for the product, customer, and resources? Useful tools are the spaghetti diagram and 5S. By eliminating unnecessary movements using the 5S technique, the time required for a hospital maintenance department to clean a functional storage area was reduced by half.
3. Get rid of obstacles: Where are the quality issues making it necessary to carry out a rework? Can you change something in this step of the process to help you avoid these quality problems? Can you make the process more Poka Yoké (Mistake proof)? Take the SIM card in your mobile phone, for example. Simply by making one corner of the SIM card a little different from the others there’s only one way to place it into the phone, thus eliminating the possibility of error.
4. The smallest possible waves: When it comes to flow, 1-piece-flow is the ideal, as this avoids having to wait for the entire batch to be ready before continuing the process. Just imagine that you have 5 steps in the process, each lasting 1 minute, and you have a batch size of 10. It will then take 50 minutes for these 10 products to be ready. Do this in a 1-piece-flow, however, and the 10 products will be ready after just 14 minutes. If you aim to move from a batch size approach to a 1-piece-flow, then set-up times need to be reduced as much as possible – a popular tool to help achieve this is SMED.
5. Build it up slowly: The last tip I would certainly like to give is that it is not easy to implement this throughout the organization all in one go. You are best starting with the part of the organization that provides the most value to the customer.
For a long time, I found flow to be a rather abstract principle. Now that I am training for a marathon and participate quite regularly in running events, I understand the concept, not to mention it’s importance, better than ever.
I challenge you to run through your organization’s processes. I’d love to get your feedback. Are you going with the “flow”?