Main > frePPLe Tutorial > Some modeling concepts
In the next section you'll build a first model. Some data elements (such as locations, customers, demands, ...) required for a model don't need an elaborate explanation.
The modeling concepts of operations, material and capacity consumption however need some introduction to get you started quickly.
The key modeling element is an operation, which defines an activity.
Example:
Operations consume and produce material through flows.
Material is stocked in buffers and a flow defines an association between the operation and a buffer. Flows thus represent the Bills of Material / BoMs in your model.
Example:
A first flow to consume 1 units of a buffer "subassembly Y" at the start of the operation.
A second flow to consume 2 units of a buffer "component Z" at the start of the operation.
And finally a third flow to model the production of 1 unit of product X when the operation finishes.
Operations also require capacity, which is modeled through loads.
Capacity is available in resources and a load defines an association between the operation and a resource.
Example:
A first load to model that machine "assembly line" is required to perform the operation.
A second load to model that an "operator" is also needed.
An operation only statically defines the activity, and doesn't specify any planned dates or quantities. Concrete activities are then instantiated in operationplans.
Example:
Another instance of "Assemble product X" is planned the next day from 3pm to 4pm for 6 units to meet another customer demand.
Another instance of "Assemble product X" for 20 units is planned today to replenish a buffer storing the product X to its safety stock level.