Each User Journey created during the individual/pair/sub-group brainstorming will contain different tasks to achieve the outcome, in the same way that we all have slightly different ways of getting to work in the morning.

The aim is to bring those various ideas together so that we create one User Story Map showing all possible alternatives.

The following diagram illustrates how we lay out the map:

It will involve a degree of de-duplication that is, removing tasks which are worded differently but perform the same task. It will also involve expanding the timeline from left to right as we merge multiple timelines, because some may be more descriptive than others. This just means more detail, and it's probably better to be more verbose at this stage than not. 

We'll also begin to see tasks which have the same outcome but take different steps to get there. For instance, using the task DECIDE TO PURCHASE STRAIGHT AWAY as a reference point, we can see that the group thinks there are alternatives to just clicking on a Buy now button. Instead, our customer might decide to put an item in the shopping cart so they can purchase it later along with other items. They might decide the item isn't what they were after and decide to continue browsing. They might do both, put the item in the shopping cart, and then keep browsing.

At this stage, don't worry too much about the ordering of the alternative paths; just place them on the map so they sit below their similar/related tasks. At this stage, we should focus on creating a timeline which represents every single step our user takes to reach the outcome. It doesn't matter (yet) how they achieve it or that there are alternative ways of accomplishing it—we're just trying to create a complete picture.