Establish “things that matter” (TTM) matrix to help steer discussion toward complexity.
This is a simple tool to help explore the complexity of the story and so assist in properly establishing the estimates relative size. A TTM Matrix consists of a list of technologies (or any other issue such as “complex testing”) that are needed to deliver the story. The technologies are list at the top of the matrix so that there are entries for each user story. For each user story, the team fills in the box under the user story if there that technology is involved in the implementing the user story. This could be as simple as an “X” or a more complex “L, M, H” type rating.
The theory is that a user story which only has a couple of boxes filled in would be less complex to implement than one that crosses a lot of things that matter and so would warrant a higher relative estimate.
Teams today are trained to use this concept so this should be a reminder. Stabilize estimates by establishing team guidelines for size. This is a modification of the Establish Points Guidelines for Each Point Value for each point value and leads to more discussion based on the important things to consider.