When SAFe, short for Scaled Agile Framework, was first introduced to help large organization implement Agile and enable them to adapt to the changes faster it naturally came with its own prioritization method too.
Weighted Shortest Job First (WSJF) prioritization model helps calculate and understand what is the level of financial impact of not finishing the task or implementing the solution sooner than later. It's called Cost of Delay.
This technique is build to speed up delivery of value in especially in large projects where the big queues of issues can build up and waiting times are getting longer and longer.
How to use WSJF method
To calculate Cost of Delay and WSJF score we need to first assign four metrics to our priorities - Business value, Time criticality, Risk reduction and Estimated size.
Ask the question "How does this impact our business" and try to look at it from different angles. If you have your Goals or OKRs set you can see how much this task helps you to get closer to completing these.
- 1 for Lowest value
- 5 for Low value
- 8 for Medium value
- 13 for High value
- 20 for Highest value
Now it's time to asses "Is there a fixed deadline? Can we loose customers if it isn't completed in certain time?" Tasks with more tight and sooner deadlines have Higher Time criticality than ones with more loosen ones.
- 1 for Lowest
- 5 for Low
- 8 for Medium
- 13 for High
- 20 for Highest
This metric is great addition to the first one - Business value. Here we're asking "Is there any negative impact if we delay?"
- 1 for No risk
- 5 for Low risk
- 8 for Medium risk
- 13 for High risk
- 20 for Highest risk
Last question we ask is "How difficult is this to deliver" You can try to estimate how long it would take to deliver this task if one person would work on this in months. But you can also use T-shirt sizing to make it a bit easier.
- 1 for XS
- 5 for S
- 8 for M
- 13 for L
- 20 for XL
The WSJF score
Now when we have all metrics we can start calculating the score.
To calculate the Cost of Delay sum up first three metrics - Business value, Time criticality, Risk reduction.
To get the actual WSJF score that gives your prioritization also context of work spend on the task you can use following formula:
The bigger the WSJF score is the higher up the task is in priority.
"If you prematurely invest all your time and money on the wrong idea, you have nothing left to try new ideas." - Alberto Savoia