• Not defining the project’s goal and objectives
• Not involving the right stakeholders
• Not probing to understand the real need (i.e., being an order taker)
• Not utilizing an organized process
• Including design components (i.e., how and not what)
• Not reviewing and conducting walkthroughs
• Not developing use cases
• Not gathering all requirements
• Guessing at requirements
• Not considering interfaces

Let’s take a very simple example.  Suppose you are developing requirements for a soup ladle:

The components of the ladle are the handle, the bowl, and the stem.  In order to gather complete and accurate requirements, you must understand the purpose of these components:

• The handle is to allow the ladle to be held by an individual without spilling the contents of the bowl or getting burnt.  
• The bowl is to hold the food or liquid contents.
• The stem is to allow enough depth into the pot or container to scoop the contents.  The stem also serves to ensure stability to avoid spilling the food as it is transferred to a plate or bowl.  

We can say, then, that the purpose of – or requirement for -- the ladle is to allow the transfer of food and liquid from a container to a plate or bowl without spillage or getting burnt.

The ladle has many interfaces:

• It can be held in a human hand
• It can be filled with food or liquid and emptied
• It must provide the ability to deliver food and liquid to a plate or bowl
• It interfaces with a table or counter and must be able to rest on a flat surface
• It interfaces with the pot or container and must provide the ability to dip deep enough into the container to scoop its contents.  By the way, how deep must it dip?
• It interfaces with a hook to hang the ladle
• It interfaces with the human mouth for those chefs who want to taste!

By examining these interfaces, many thought provoking questions arise that must be discussed and explored.  For example, must the ladle provide a way to strain the contents as they are scooped?  I once used a ladle that not only allowed you to strain the contents, but it also contained a slot-pin fastner that allowed you to adjust the quantities of solids entrapped by the straining element.  If that’s a requirement, it would certainly be good to know!  It is by observing the interfaces and considering the overall purpose of the ladle that additional requirements are discovered.

Other observations include:

• The ladle is useless on its own; it requires a human hand and arm to fulfill its purpose.
• It must be used in a certain way; holding the ladle upside down would cause spillage and possible scalding.
• The bowl part of the ladle depends on gravity for it to function correctly.  In a weightless environment, the ladle would not work and a different mechanism would be required.
   

While many more examples could be explored to demonstrate the significance of the requirements process, the bottom line is this:  the engineering of requirements must consider the components of the product, how those components interact with the interfaces, and the nature of the enveloping systems and environment in which the product must work.  Requirements gathering is an art that must must follow a process and must involve the appropriate stakeholders in a collaborative effort. 

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