Abstract Wikipedia team/Work-estimation

Overview

The Abstract Wikipedia team uses retroactive and forward-looking estimation to help us plan quarterly work.

Retroactive Estimation

As a team at the end of each quarter, we each indicate how much time we spent on each project using t-shirt sizing. We compare this to what we expected at the beginning of the quarter, and have a discussion around the outliers. Over time this has led to a better understanding of what’s involved in different types of work, and better forward-looking estimation.

Forward-looking Estimation

When we plan the next quarter, we create a prioritized list of projects, then estimate each one at a high level. This gives us an overall idea of feasibility, and we may re-scope, de-prioritize or defer projects based on this exercise.

In future iterations, we would like to do a bit more work break-down prior to this exercise to help us plan even better.

Process

In the Roadmap & OKRs document where we do our planning, there is a section to the right of each project where team members can enter their t-shirt size estimates:

Figure 1: estimation tool for one of the projects in a quarterly plan.

For retroactive estimation, there is an “Actual” row to enter our t-shirt sizes. The table makes it easy to see if actuals are significantly different from estimates, so we can focus our discussions there.

For forward-looking estimation, each person enters their t-shirt size in their own column on the “Estimate” row:

• Number of projects: For each person’s column, row 2 totals the number of projects containing an estimate. This shows you how many projects you expect to be involved in.
• Total person weeks: Row 2 also shows the total number of weeks each person has estimated for themselves. Since there are 12 weeks in a normal quarter, and actual working time is closer to 8 weeks (assuming 30% of our time is spent in meetings and overhead work), each person should check if they come around that number. If your number is far above 12 weeks, this tells us you might be over-committed.
• Team sizing: Columns N and O show the total sizing for the team for a particular project. In the example above, we expect this project to be an XL effort.

Figure 2: estimation tool showing more of the projects in a quarterly plan.

Figure 2 shows how the estimation tool looks next to multiple projects:

• Priority indicator: The more weeks a project is estimated to take, the darker the green shading in column O. Since higher priority projects usually take more effort, we can conclude from this figure that we have prioritized correctly. The background shading should go from dark to light as you read down the list.
• Total team weeks: As another feasibility check, we can select the values in column O to see the total. On a 12-person team in a 12-week quarter, we should expect to see a number close to 100 weeks, assuming 30% of our time is spent in meetings and overhead work.

Sizing Charts

Individual:

• XXS = <1 day
• XS = <1 week
• S = 1-2 weeks
• M = 2-4 weeks
• L = 4-8 weeks
• XL = 8-16 weeks

Team:

• XS = < 5 person-weeks
• S = 5–10 person-weeks
• M = 10–20 person-weeks
• L = 20–30 person-weeks
• XL = > 30 person-weeks