Weighted, Shortest Job First (WSJF):
Prioritizing for the greatest economic outcome
So, How do you determine the right projects and features to do at the right time? Well, an excellent tool to use to this is called weighted, shortest job first (WSFJ). Go ahead and download the WSJF Tool and read this article to learn how to use it.
I’ve used this technique to objectively align stakeholders such as business owners, architects, and product managers in prioritizing roadmaps. This technique is so powerful because the cost of delay has a big impact on the ability of a team to operate productively. As Don Reinertsen said…
If you can only quantify one thing—quantify the cost of delay. (Reinertsen, 2009)
What is Cost of Delay?
Cost of delay is value lost during the period of time the job is not implemented.
How does WSJF provide special value?
So of all the prioritization scoring models out there, what makes WSJF so special?
WSJF takes quantifying the cost of delay a step further and also informs decision-makers about the best sequencing for the work. This is important because job sequencing is a key to optimizing economic outcomes.
Basically, WSJF helps teams to give preference to the efforts that are the most weighted, meaning they are the most impactful job with the quickest route to completion.
How does WSJF work?
WSJF is basically the Cost of Delay divided by the job size or job duration.
The Cost of Delay is determined by the sum of Business Value + Time Criticality + Risk reduction or Opportunity Enablement.
How to use the WSJF Tool?
Important Tips:
- If you haven’t done I before, I recommended trying the tool out with a personal example. Doing this helps you to better digest how to apply the tool and makes it easier to relate to.
- For scoring, I recommend using the Fibonacci series as your scale. In a Fibonacci Series, each number equals the sum of the previous 2 numbers. Example: 0, 1, 2, 3, 5, 8, 13, 21. Using this series as your scale makes it easier to get a consensus and not spend time splitting hairs.
Alright let’s jump straight into an example:
So a few months ago I had a lot of tasks to do and very little time I used the WSJF Tool to help me prioritize my personal tasks. Here are the steps I followed to complete the table below:
- Write out all of my features in the “Work Item” section.
- I first judged the lowest score (1) for each column.
- From there I compared each dimension in each column to this. This method is called relative estimation. It makes scoring easier because you are comparing the value based on how it compares to another item.
- When all of the white columns are filled in, the Cost of Delay and WSJF is calculated. What we want is the WSJF.
- Organize the WSJF from highest score to lowest score and prioritize the features in this order.
At the end of the exercise, to my dismay the conclusion was to complete my car title paperwork first. Compared to the other tasks, it had the highest cost of delay and was the smallest in size.
If you objectively do this exercise, you’ll likely find that the outcome is often not what people expect.
Now, this is not meant to be a hard science. It’s meant to inform and drive conversations, and possible planning adjustments. For example, you could consider allocating another developer which would reduce the job duration. Doing this will increase the WSFJ score and priority. The goal here is to drive conversations and plan for the greatest economic outcome.
I highly recommend you incorporate this free tool to support your teams. WSJF helps to drive the conversations needed to align decision-makers in determining the best order to implement your features.
If you want to learn more details about WSJF and how to implement it, check out these resources:
iZenBridge. (2020). Weighted shortest job first (WSJF) in SAFe [Video file]. Youtube. https://www.youtube.com/watch?v=tI8hvuaExOY
Scaled Agile Framework Inc. (2021). Weighted shortest job first. https://www.scaledagileframework.com/wsjf/
Written By: D. Roland