Don Reinersten, in the Principles of Product Development Flow: Second Generation Lean Product Development, describes a mechanism called Weighted Shortest Job First for prioritizing work. You can read more about the method in the Scaled Agile Framework’s abstract, but the idea itself is simple and sensible. You use economic theory to prioritize your work by factoring the cost of delay divided by job duration. There are four factors that go into the equation: business value, time criticality, risk reduction or opportunity enablement, and job size. This sounds great in theory, but how does it really work? How can we use this in conjunction with our other visual models?
Our Business Objectives Model, it turns out, is great for this. It allows us to very easily arrive at relative business value scores by comparing the dollar value of each feature presented in the model. In this example, we have three different features proposed. One has a value of $75,000 (create wishlist), another of $225,000 (share wishlist), and a third is worth $20,000 (mobile-friendly site enhancements).
You can use a simple template in Excel to compile summary information for each feature (see example below), as well as its associated value identified by the Business Objectives Model, and start scoring using the modified Fibonacci sequence (1, 2, 3, 5, 8, 13, 20). Ideally, you’ll have business stakeholders and IT represented to play planning poker to arrive at scores for each item. The rule is that every column has to have at least one value of “1” assigned. So, you start with the smallest value item, and then relatively score the other items in the list. You go one column at a time through the template, and calculate the total score with the following equation:
WSJF = (Business Value + Time Criticality + Risk Reduction or Opportunity Enablement)/ Job Size
Business Value: For business value, since we’ve done our Business Objectives Model, we know that the mobile-friendly site enhancement is the lowest value feature in the list, at $20K, so this feature gets scored a 1 in the business value column. Create Wishlist is almost four times that valuable, but not quite, so we’ll give that one a “3”. Share Wishlist, with a whopping $225K of value associated, is almost 12 times as valuable as the mobile-friendly feature, so we’ll score this one with a “13” (since it’s closer to 13 than it is to 8).
Time Criticality: How quickly do we need to launch the feature? Will the value decay over time? Are we losing revenue because we’re not implementing it now? In this case, the least critical item is again the mobile-friendly site updates. The company has been considering the feature for ages, but mobile shopping doesn’t seem to impact their core demographic. Their core demographic likes shopping online through laptops and PCs but trends away from shopping on the go with mobile devices. In order to increase mobile shopping, the company feels they would need to change their product offering to target younger audiences. With competitors adding wishlists to their sites and seeing a lift in purchase conversion rates, the company knows that they have to get on par in the market, or they could start losing customers who prefer to think longer about their purchases (and save them for later). This is such an important initiative for the company that they feel it’s 20 times more urgent than the mobile updates, so this one gets scored with a “20”. Share Wishlist is an important extension of the wishlist initiative, but it can’t be launched until Create Wishlist is live. So, while it’s time critical, it’s less than half as critical as getting the core functionality out the door and getting shoppers adding items to their wishlist, so it gets an “8”.
Risk Reduction/Opportunity Enablement: Share Wishlist will enable some future opportunities through gifting marketing campaigns and addition of custom notifications and reminders, but this is estimated to have a small impact, and it doesn’t alleviate much risk compared to the other two items, so it gets a “1” for this category. The company thinks that investing in mobile-site updates COULD support targeting younger demographics and expanding the customer base, so this is given a score of “5”. The company fears that without implementing wishlist functionality, they’re at risk for losing some customers to competing sites, so this is scored with an “8”.
Job Size: Here’s where the developers weigh in. First, we determine what the easiest feature is to build, and from there relatively score the others. The technical team votes and rates Share Wishlist a “1”, Create Wishlist a “5”, and mobile-responsive site a “13”.
We can plug our numbers in and see that Share Wishlist is the clear winner, with the highest score of 22. Because we know that Share Wishlist has a dependency on Create Wishlist, the team embarks on delivering MVP (minimum viable product) wishlist functionality quickly, so they can start to achieve the real value with Share Wishlist functionality.