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Managing Resources Using Configuration Rules

The most common way to manage a resource is to write provide and consume rules that add or subtract the value of an attribute from the resource. For example, you could write a configuration rule that contributes the number of slots in a chassis to a resource called slots available. You could also write configuration rules that consume slots from the resource when the user picks an expansion card.

By convention, the value of a resource must exactly equal the sum of all the contributors to the resource. Rules that consume or reduce the amount of a resource are negative contributors. The value of a resource is a computed value and cannot be directly set by a configuration rule.

For example you define resource R. You then write a configuration rule that sets the value of R to 5:

R ==5

When you validate the customizable product, this rule will be rejected by the system because it sets the value of R at an arbitrary value rather than allowing the value of R to be computed as the sum of all its contributors.