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Frepple’s solver algorithms

 

FrePPLe provides 2 solvers, each designed for specific supply chain structures:

  • the default solver is designed to handle complex and deep manufacturing supply chains.
  • the distribution solver is designed to solve large scale supply chains with purchasing and distribution activities, without manufacturing operations.

 

MANUFACTURING SOLVER

DISTRIBUTION SOLVER

Designed to solve complex and deep manufacturing supply chains.Designed to solve distribution supply chains with purchasing and distribution activities.

Solves demand by demand.

The algorithm orders all demands by priority, then due date. Next, the algorithm iterates over the demands and plans for all the material and capacity it needs.

 

 

 

 

 

Propagates demand level by level.

All demands are first planned at the customer demand location level, then propagated level by level upstream in the supply chain, up till their purchasing location. Next, all supply and lead time constraints are solved, first at the purchasing location and then propagated downstream towards the customer demand location.

Constrained supply is allocated to the the most important demands.

When the first demand with the highest priority and/or the closest due date is planned, it will get allocated the 10 pieces we have available.
The second demand will be planned late or short.

Supply constraints are proportionally divided across all impacted demands.


The supply shortage is equally divided over both demands. They both get satisfied 50% on time and 50% late or short.
See this example model.

Plans for sales orders, forecast, and safety stock.Plans for sales orders, forecast, and safety stock.
In the absence of any demand, it can also push excess inventory downstream in the network. See this example model.

Supported functionalities:

  • complex resources (including alternates, skills, setup matrices, bucketized or continuous)
  • location and supplier availabilities (to model vacations)
  • alternate supply paths (alternate resources, make-or-buy, alternate suppliers, etc.)
  • …

Supported functionalities:

  • only simple resources constraints
  • location and supplier availabilities (to model vacations)
  • alternate supply paths (alternate suppliers, buy-or-ship, alternates transport modes, etc.)
  • …

 

The configuration parameter “plan.solver” specifies which solver algorithm frePPLe uses. When this parameter is set to “heuristic”, we use the manufacturing solver when executing the “Generate Supply Plan” task. When set to “distribution”, we use the distribution solver instead.

Note: with some customizations, we could combine both solvers and solve different parts of the supply chain with different solvers.

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