In-Out List

What is it?

The In / Out List is a project work scoping device discussed by Alistair Cockburn in his book Writing Effective Use Cases, and which he also covered in an article about the book. It's very simple to create and use, and facilitates discussion among stakeholders on exactly what is in or out of scope.


Why do it?

According to Cockburn, the benefit of the In / Out List lies in both its simplicity and it's ability to foster discussion and consensus among stakeholders. By creating the List as past of early stakeholder group discussions, you immediately surface disagreements about the scope of the work to be done and possibly even the objective of the work.


How do I do it?

Creating an In / Out List is extremely easy and can be done in just a few simple steps.

Step 1

Create a 3 column table with the first column being wide enough to enter a short statement, and the second and third columns just being wide enough to enter a 3-letter word.

Step 2

Label the first column Topic, the second column In, and the last column Out.

Step 3

Enter the first topic you wish to discuss on whether it is in or out of scope into the first row of the Topic column. This should be reasonably specific, such as creating an invoice, but can start out at a higher level and eventually be refined.

Step 4

Discuss among the stakeholder group whether the topic is in scope or not. Once a consensus is achieved, mark the appropriate result column (the In or the Out).

Step 5

Repeat as necessary until the overall scope is relatively clear and all known areas of potential disagreement are addressed. The current version of the In/Out List should be available during any project team / stakeholder / or sponsor meetings and can be updated on the fly as new issues are found or if old decisions need to be revisited.


What Should the Results be?

The result should look something like the table below:

Topic In Out
Order System In
Invoice System In
Payment System In
Payment Processing Hardware Out
Analysis of Current Systems In
Accounting System Out
Delivery Management System Out

Or you can check out this actual In/Out List that was created for the Robert C. Byrd Green Bank Telescope.



The greatest advantage of this technique is it's simplicity. It's easy for anyone to understand and it's easy to maintain.



The are two potential disadvantages to the In / Out List that come to mind.





  1. Article - Use Cases: Defining Scope. By Alistair Cockburn. InformIT. March 22, 2002
  2. Book - Writing Effective Use Cases. By Alistair Cockburn. Addison-Wesley. 2000. Pgs. 35-36

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