10 April 2009

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Why Use a WBS or… Try Shopping Without One
By Kevin Archbold, PMI-SP, PMP

The topic for this article was inspired by a submission from Terence Chau, who is located in Hong Kong and has worked in project management for eight years.

You all know that scope management and work breakdown structures (WBS) are an important part of project management.  Or do you? 

I often get asked if you really need a WBS, or if you can just get by with a network diagram or a Gantt chart. Of course I can answer that question, but I’d rather paint you an illustration and then let you decide!

Let’s imagine that you are planning a trip, or a project, to buy groceries for a party that will consist of several complicated recipes.

Of course, before you leave, it’s a good idea to create a list of items you need to buy.  If you don’t create a list, you are likely to forget something or buy things you don’t really need. Suppose, though, that you don’t just create a list, but you create a WBS hierarchy.

Here’s how you might arrange it: You draw a box that says, “Buy groceries for party.”  Under that, you have boxes for each location/store that you need to visit.  And under each store, you draw boxes for different types of groceries—buy dairy, buy produce, and so on.  Finally, under each grocery type, you list the actual purchases—buy milk, butter, grapes and so on.

What’s the advantage of this hierarchy over a simple list? 

1. As you systematically create the hierarchy, it might remind you of similar items that you might have otherwise forgotten to buy.
   
   
2. When someone asks if you have remembered to include a particular item, it’s a lot easier to find the answer in a hierarchy than it is in a list of items in random order. 
    
   
3. Your hierarchy can provide summary information and organization, such as the categories of groceries you are planning to buy, and the locations you plan to visit. This information can help you sequence your activities.
   
   
4. When a family member asks if you can “just pick up” an extra ingredient, you can more easily assess whether this request requires a significant change to your plans, perhaps requiring an extra stop, or whether it is simply a minor addition to your current plan.
   
   
5. If one or more people will help you buy the groceries, it is much easier to explain what needs to be done, and to determine how to divide up the work.

When you are actually out shopping, the WBS comes into play again:

1. Reducing the probability that you will have to go back to the produce store because you missed the fact that someone added lettuce to the very bottom of the list.
   
   
2. Reducing the likelihood that you buy additional but unplanned items, perhaps magazines and candy, that are seemingly inexpensive, yet end up causing you to exceed your budget (Scope creep).
   
   
3. When your sister calls you half-way through the trip to request you add in some expensive fish, you can more easily assess how to afford this purchase and what can be dropped to help you stay within your budget (Scope change).

So while you could use a simple task list, a WBS will definitely help you to plan and execute your project — and even your shopping trip — more effectively. 

This article was contributed by Kevin Archbold, PMI-SP, PMP, who has 20 years of project management experience with large and small organizations in various industries including automotive, nuclear power, telecommunications, trucking, IT, human resources, biotech, and government.  Mr. Archbold has been a member of PMI since 1991, serves as the current President of the PMI Tucson, Arizona Chapter, and since 1999 has been a project management consultant and trainer through Key Consulting. He welcomes your questions and comments.