What is Weighted Shortest Job First (WSJF)?
Weighted Shortest Job First (WSJF) is a tool used in the Scaled Agile Framework (SAFe) to help teams prioritize a list of initiatives. A team calculates each initiative’s score as the cost of delay divided by the job’s size or duration. The team then prioritizes those items that receive the highest ratings.
How WSJF is used?
Any team in an organization can use the Weighted Shortest Job First approach to sequence any initiatives. Marketing teams can use it to determine which projects or campaigns will give the company the highest return on investment. Product teams can use it to decide which items to prioritize on the product backlog.
How is WSJF calculated?
Often, Weighted Shortest Job First is a simple formula: Cost of Delay divided by Job Duration (or Size).
Step 1: Calculate Cost of Delay
To arrive at the Cost of Delay figure, however, we will need to do a few additional calculations.
As the training company Scaled Agile explains, Cost of Delay in the WSJF framework is three components:
1. Value to the business and/or user
2. Time criticality
3. Risk reduction and/or opportunity enablement
To calculate the Cost of Delay, you will create a scale for each component (for example, 1 to 10) and add them up. The combined number of all three parts will equal your Cost of Delay score.
Step 2: Calculate Job Duration (or Size)
Next, you will set a scale for the job duration or size of each initiative on your list. The scale can be different from your Cost of Delay scale (for example, 1 to 20) as long as you are applying it consistently to all initiatives.
As TechBeacon explains, calculating job duration in WSJF can be difficult. Your current resource levels, dependencies, skill sets, and other factors can make a project more time-consuming or taking longer at your company than it might at others.
But your team will need to agree on a methodology for assigning a number value to each initiative on your list. When determining job duration or size, the lower-number items will become your higher-priority initiatives.
Step 3: Divide Cost of Delay by Job Duration (or Size)
The final step is to divide your Cost of Delay by Job Duration for each initiative on your list. Prioritize the initiatives with the highest overall scores at the top of your list.
For example, let’s assume you’ve scored one initiative on your list with a Cost of Delay of 9 and a Job Duration of 1. That initiative’s WSJF score will be 9, or 91.
Now assume you’ve scored another initiative this way: Cost of Delay = 7 and Job Duration = 4. That initiative’s WSJF score is only 1.75, or 74.
As you can see, initiatives with higher Cost of Delay scores earn a higher position on your WSJF list. Initiatives with lower Job Duration scores also receive a higher WSJF priority.
How to Use Weighted Shortest Job First to Prioritize Items on a Product Roadmap
When several initiatives compete for limited time and resources on your product roadmap, Weighted Shortest Job First helps you determine which items to prioritize.
You can follow the steps outlined on this page, calculate a score for each item on your backlog, and then select the highest-scoring items for the top positions on your roadmap.