Ah yes, flow efficiency.
An agile metric that often sits on the bench while related metrics like throughput and cycle/lead time get all the attention. While some metrics focus on completed work and others measure the time taken to complete it, flow efficiency examines the gaps in between.
Let’s dive into what that means, and how impactful flow efficiency can be.
What is flow efficiency?
Well before answering that question, I want to use a relatable example. The scenario I often use is the one about packing boxes, before moving into a new home. We will use this example to explain flow efficiency.
Let's say that you dive right in, and make a promise to yourself that you will pack 6 hours each day, starting 9 in the morning till 3 in the afternoon. You pack boxes for three days, and this is the result of your hard work:
- Day 1: You packed 5 boxes.
- Day 2: You packed 6 boxes.
- Day 3: You packed 4 boxes.
You packed 5 + 6 + 4 = 15 boxes in total, and you did all that in three days. Is that efficient? We don't know, because we are only looking at how many boxes were packed each day. Let us try to zoom in on Day 1 where you packed 5 boxes, and understand what actually happened:
- 9 am to 10 am: You eat late breakfast.
- 10 am to 11 am: You sort your belongings, and what you want to pack today.
- 11 am to 12 pm: You take a break by watching an episode of a tv show.
- 12 pm to 1 pm: You pack 3 boxes.
- 1 pm to 2 pm: You watch another episode of your tv show, it's addicting!
- 2 pm to 3 pm: You pack 2 boxes.
Out of the 6 hours that you dedicated to packing boxes on Day 1, you worked actively for 3 hours. 1 hour by sorting belongings, and 2 hours by packing. The rest of the time, not that much work was done.
Flow efficiency measures the rate of your efficiency. 3 out of 6 hours, is a rate of 0,5 or 50%. That means that your flow efficiency is at 50% for Day 1. Let's say we did the same exercise for Day 2 and Day 3. Your flow efficiency for the three days of packing boxes:
- Day 1: 50% (5 boxes)
- Day 2: 60% (6 boxes)
- Day 3: 40% (4 boxes)
Looking at your data, there is certainly room for improvement. Half of the time, you are not packing any boxes. Maybe you should start eating breakfast earlier, or skipping the episodes of your tv show? Regardless, your flow is not efficient, which is why this metric is named as flow efficiency.
So, as mentioned earlier, flow efficiency includes the gap that many other metrics lack. It includes inactive time, so the result of the metric is your efficiency in actively working on something.
If you use this metric for teams, it would help in showing inefficiencies, bottlenecks, wasteful work, and potential delays in a workflow. Visualizing flow efficiency on a chart, and understanding the trend will also help you improve and plan for unexpected inactive time. There might be good reasons for the low flow efficiency, but you need to uncover the root causes with this metric before you can draw that conclusion. At the same time, having high flow efficiency means that the work goes smoothly, but understanding the dynamics behind it could lead to learnings that will improve your team even more.
Now, let's get to the simple definition of flow efficiency, so we can remember it!
Simple definition of flow efficiency
Flow efficiency is the percentage of time spent actively working on something versus the total time spent.
