Remember - WBS is about grouping tasks. It is not about sequencing tasks (not yet at least). So right now you are concentrating on getting the tasks into the right group. Why do we put them in a group? Because that is extremely helpful in two ways:
First, it helps us break the project down into little mini-projects (called summary tasks). This gives us a sense of the key deliverables that together contribute to the completion of the overall project.
Second, when you begin analyzing the tasks needed to complete those little mini-projects (summary tasks) within your big project, it is easier to make sure you account for everything. It's kind of impossible to think of all the tasks that go into building a house when I'm thinking about the project as a whole. But if I look at each summary task separately (for example, just the plumbing), then I can concentrate on every individual task (called work packages) that is needed in order to complete the plumbing work on the house. When that is done, I can think about the the summary task of getting electrical installed by listing all the individual tasks (work packages) that are required in order to complete the electrical work on the house. And so on. Doing this makes if far less likely that I'll leave tasks unaccounted for as I build the project schedule (and budget).
1. Create a Work Breakdown System (WBS) for the following project of making brownies. (Hint: the primary summary tasks are Plan, Prepare, Baking, and Cleanup. There is one extra small summary task in there if you can find it. It is subordinate to the "Prepare" summary task.)
Pour batter in pan
Bake in oven
Gather ingredients
Let brownies cool
Test with toothpick
Turn off oven
Check ingredients at home
Read recipe
Remove from oven
Wash dishes
Preheat oven
Gather baking pans and mixing bowls
Mix other ingredients in bowl
Mix ingredients
Grease pan
Go shopping
Melt butter and chocolate in microwave.
Make sure that each summary task and subtask is numbered. See the chapter for examples on numbering systems. Tasks without numbers can't be tracked and referred to by project planners. It's like a house without an address - it ain't gonna get any mail.