4. Flow-Optimise Anything!

Flow is key to nearly every situation. Improving flow dramatically improves the situation dramatically. It’s quicker and easier than you think.

Flow-Rate and Flow-Time
There are two ways to accelerate flow:increase flow-rate and/or reduce flow-time
Flow Dimensions

There are two dimensions to optimising flow:

  1. Flow-RATE Acceleration and
  2. Flow-TIME Reduction

They’re closely related – and affect each other – but  are not the same thing.

Flow-Rate Acceleration is getting more out – increasing the rate at which the system or situation produces stuff.  Think: higher frequency; more units or quantity per time; more dollars per month; more products per hour; more good experiences per week.

Flow-Time Reduction is getting things done faster – reducing the time per unit.  Think: shorter lead-time; less time to break-even; less-time to make each product; quicker response times; less delay.

How to increase the flow-rate

The flow-rate lever is the situation or system bottleneck.

What determines the end-to-end flow-rate?  The bottleneck.  (There is nearly always only one bottleneck, at any point in time.)

What about non-bottlenecks – don’t they also affect the flow-rate?  No, they don’t – not directly.  If they did, they would be the bottleneck.

How do you increase the flow-rate?  By increasing it through the bottleneck.  Be warned, though: the bottleneck is only there because it’s difficult to widen.  If it was easy, it would have been widened already – and the bottleneck would be somewhere else.

The natural tendency is to leap to buying more bottleneck capacity, but this is both wasteful and unnecessary, in most situation.

Here are some counter-intuitive steps for getting more through the bottleneck without leaping to buying extra capacity:

Flow-Rate Acceleration Steps
  1. Draw the flow.
  2. Find the bottleneck.
  3. Introduce QC before the bottleneck.
  4. Optimise the bottleneck.
  5. Choke the in-flow.
  6. Buffer the bottleneck.
  7. Introduce pre- and post-processing.
  8. Finally: Add bottleneck capacity.

Click here to watch the video, if you like – or read The Goal by Eliyahu Goldratt.  Click here for a detailed post on the Flow-Rate Acceleration steps.

Very few people or organisations have consensus on where the bottleneck is within their situation – and hardly any are taking deliberate steps to relieve it.  The result?  Flow-rates reduce rather than increase over time: even with extra effort.

How to reduce flow-time

The flow-time reduction opportunities are:

  1. Every step/process/task on the critical path sequence
  2. Occasions when the critical path changes
  3. Handover delays
  4. Every activity done by critical resources (humans or machine working on critical path steps).

I call these lead-time contributors.

As a rule, the biggest lead-time contributors provide the biggest leverage opportunity.

The lead-time levers are common elements across these lead-time contributors.  Here are the most common lead-time levers:

  1. Wait-time.
  2. Rework-time.
  3. Setup-time.
  4. Processing time.
  5. Travel time.
  6. Curing time.
Flow-Time Reduction Steps
  1. Draw a time-wheel, showing pie-slices for each category.
  2. Identify the biggest lead-time contributors.  The most common ones are wait-time and rework-time.
  3. Generate solutions for reducing the time consumed by each category, starting with the biggest lead-time contributors.  (Wait-time is often caused by flow-rate problems. If so in your case, add the Flow-Rate Acceleration steps to the list of solutions.)
  4. Keep an eye open for solutions that affect more than one category.
  5. Work out which solutions will have the biggest, quickest and most sustainable impact for the least effort and lowest cost.
  6. Implement the solutions (in series where possible), re-evaluating as you go and keeping an eye out for serendipity (more about this later).

Click here to watch the video, if you like.  Click here for details on the Flow-Time reduction steps.

Very few people or organisations have worked out what the lead-time contributors are in their situation – and even fewer are taking deliberate steps to reduce them.  The result?  Lead times go out rather come in.

Immediate gains
  1. Work out whether you would benefit most from flow-rate acceleration or flow-time reduction.
  2. Take the relevant steps, listed above.
  3. Don’t be surprised if it’s hard to identify or find consensus on where the bottleneck is or on how to shave time from the biggest lead-time contributors.  If it was easy, we would have done it long ago.
  4. It’ll be obvious in hindsight – and everyone will say that they knew it all the time.  ASk what they’re doing about it and you may hear a different story.
  5. Realise that it’s a never-ending process: in both cases.

Start a conversation on relieving your organisation’s bottleneck and reducing your lead-times by making a comment below.