What is Card Size and Why Does it Matter?

Card Size Top Image

Many teams find it useful to identify and track the size — or amount of work — associated with each work item. LeanKit lets you easily assign a size value to each card,  manage your WIP based on card size, and run reports using size as a variable.

In LeanKit, size is an optional field that you can update in the Details tab. When you enter a number into the Size field, you override the default card size of one and assign the appropriate amount of effort to the work. The card size appears on the face of a card, ensuring visibility for the entire team.

Sizing Approaches

Sizing can help teams plan and groom their backlog, understand how much work is in process at a given time, and analyze metrics such as cycle time and throughput.

Approaches to sizing — or assigning points — vary by team and can range from using a t-shirt size (e.g., 1 equals extra small, 2 equals small, etc.), a scale of 1 through 10, the Fibonacci sequence (1, 2, 3, 5, 8, 13, etc.), or a detailed estimate for hours of effort. In manufacturing, card size is also used to designate how many widgets need to be built — often resulting in much higher card sizes.

Click on a lane or hover over any sublane to see total card count and total card size.

Click on a lane or hover over any sublane to see total card count and total card size.

Once your team agrees upon an approach to sizing and captures this information for each work item in LeanKit, you have the option of using size to manage your work in process (WIP) limits.

WIP Limits Based on Card Size

WIP limits can be established for lanes, including sublanes and swimlanes, and for board users. To learn more about how to setup WIP limits, read here. Once WIP limits are established, update the setting in LeanKit to “Base WIP Limits on Card Size” (see below for more details). Once this is in place, WIP limit warnings and override events will be calculated on card size rather than the number of cards.

Here’s an example of standard WIP setup. The lane WIP limit is set to three and is based on the number of cards in each lane. These two cards have a combined size of four, but there is no WIP limit warning or override as the number of cards has not been exceeded.

Example of WIP limit that's not based on card size.

Example of WIP limit that’s not based on card size.

When a fourth card is later pulled into this lane, the system requires a WIP limit override and the lane, along with the WIP limit number, stays red until the WIP limit of three cards is once again observed.

Standard WIP limit override based on number of cards in the lane.

Standard WIP limit override based on number of cards in the lane.

Now let’s take the same example and base the WIP limit on card size. The two cards highlighted have a combined card size of four, which exceeds the established WIP limit of three and also requires a WIP limit override.

Example of WIP limit override when WIP limit is based on card size.

Example of WIP limit override when WIP limit is based on card size.

This same logic is applied to WIP limits for board users. If the setting to “Base WIP Limits on Card Size” is not selected, then the user WIP limit is based upon the number of cards assigned to the user. If the setting to “Base WIP Limits on Card Size” is selected, then the WIP limit warnings and overrides take the total card size assigned to the user into account.

How to Set WIP Limits Based on Card Size

For existing boards, click the Settings icon on the top bar. Next, click Settings from the drop-down menu. You will be on the Board Settings tab. Check the box next to “Base WIP Limits on Card Size.”

Base WIP limit on Card Size setting

“Base WIP limit on card size” setting for an existing board.

When creating a new board from the LeanKit Home Screen, check the box next to “Base WIP Limits on Card Size” in the Create New Board tab to enable the setting.

The “Base WIP Limits on Card Size” setting can be selected during initial board setup.

The “Base WIP Limits on Card Size” setting can be selected during initial board setup.

Applying the “Base WIP Limit on Card Size” setting lets you easily identify when the estimated effort associated with work in process is overloading the system or team. To learn more about limiting your WIP, read our blog post on WIP Limits: How to Journey (safely) Into the Unknown.

Using Card Size as a Variable in Reports

Teams can also use card size as a variable in LeanKit reports. Calculating analytics based on card size provides useful insight into how effectively work items are flowing through your system.  For example, rather than saying the average card takes five days to complete, you could say that the average card with a size of three takes five days to complete and then compare this to the average time a card with a size of five takes to complete.

Cumulative Flow Diagram calculated based on card size.

Cumulative Flow Diagram calculated based on card size.

 Reports Based on Card Size

To run a report based on the size of the cards on your board, click the “Calculate based on card size” checkbox found on the bottom right of the report window (below the start/end date selection fields).

Each report (including Cumulative Flow, Cycle Time, Card Distribution, Efficiency, and Process Control) has a setting option to calculate based on card size.

The average Cycle Time report shows the amount of time it takes to complete work items from start to finish.

Average Cycle Time report calculated based on number of cards.

Average Cycle Time report

Average cycle time based on card size provides additional insight into work throughput.

Average Cycle Time report calculated based on card size.

Average Cycle Time report calculated based on card size.

Understanding how work items of varying sizes move through your workflow can help in re-distributing workload, determining where larger size items get held up, breaking work down into smaller batches, and forecasting throughput for similar work.

Manage Your Work More Effectively with Card Size

The card size field is an available option in all LeanKit editions and allows you to capture estimated effort for each work item to assist in planning and managing work.  Limiting your WIP by card size and running reports using card size as a variable gives you better insights to understand where bottlenecks are occur and how to improve your flow of work.

3 thoughts on “What is Card Size and Why Does it Matter?

  1. This is nice but really what is needed is a way to track time as well as enforce this in the system. Further, why does your system not produce standard and simple burn down charts?

  2. Hi Jay,

    We don’t track time in LeanKit and don’t have immediate plans to change that. The truth is that we don’t believe tracking time is a great way to make teams productive — and that’s what we are all about as a company. Our experience has shown us that time-keeping records bear little relation to actual time spent on work.

    People (we include ourselves in past lives) make up numbers to match how much time they’ve been told they were supposed to spend on a project. A tremendous amount of evidence in management research shows that focusing on how much work a team produces is way more effective in helping them become more productive.

    If companies really must track time, we integrate with portfolio and financial management systems that handle that sort of thing better than we ever want to: Microsoft Project Server, Oracle Primavera, Freshbooks, Harvest, etc.

    As to your question about analytics, our current charts were built to help our original core customer base of lean and Kanban folks, who favor burn-up charts over burn-downs. But as we expand, we are reaching many new types of folks with different needs.

    We are in the process of overhauling our analytics infrastructure and expect to, very soon, be able to offer many more reporting options — including both activity reports for employees and burn-down charts.

  3. What would be really nice is a simple view of the backlog cards showing potential completion dates based on card sizes’ historical cycle times, and having it update as backlog cards are shuffled around. I would imagine many teams would benefit from this visibility when making decisions around backlog prioritization, and right now it requires (from what I can tell) a significant amount of manual calculations to even come close to modeling it out correctly. 🙁


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