The estimated cost is the cost an organization expects to pay for the delivery of a service associated with a specific type of service plan item. Depending on the business requirements for a plan item of a particular type, the estimated cost may be derived from the plan item definition, using the cost attribute of the PlanItem entity, or the cost can be entered by the user. For example, an organization has defined a Car Repair and a Bus Pass Provision plan item. The Car Repair plan item is intended to pay for repairs to a client's car to enable the client to travel to and from a place of work. The Bus Pass Provision plan item is intended to provide the client with a bus pass for one year, thus enabling the client to attend work. The bus pass provided by the organization has a fixed cost, whereas the cost of car repairs can vary considerably. Therefore, the plan item definition for the Bus Pass uses the PlanItem entity's cost attribute to define the estimated cost of the plan item to the organization (in fact, as this cost is fixed, this also defines the actual cost to the organization). The value of the PlannedItem entity estimatedCost and actualCost attributes are set to the value of the PlanItem entity cost attribute.
The pages defined to add and modify a plan item of this type should not allow the user to modify either the estimated cost or the actual cost. However, as any type of vehicle repair can be facilitated by the Car Repair plan item, it is not possible for the organization to define a realistic estimated cost. Therefore the estimated cost to carry out the car repair must be entered by the user when the plan item is added to a service plan. The pages defined to add and modify a Car Repair plan item should allow the user to set the estimated cost of the repair. The estimated cost may also be derived from a product provision. A product provision is the delivery of a service by a provider at a specific location. For example, an organization has defined a plan item to provide basic computer skills training. Providers have been registered with the organization that offers this type of training at a number of different locations at different costs. The cost of delivering the service depends upon the provision (a combination of provider and location) selected. Therefore the estimated cost of a plan item added to a service plan to provide this type of service derives its estimated cost from that specified for the product provision.