frePPLeOpen source Production Planning
  • Home
  • Documentation
  • C++ API

Demand solver

The algorithm goes through the following pseudo-code to plan a single demand.
It will call the operation solver to plan the delivery operationplans of the demand.

Ignore the demand if quantity is 0

Erase previous delivery operation plans, except the ones that are locked
Optionally, the Enterprise Edition can also erase upstream supply

Clear the list of constraints of this demand

Find the delivery operation, either defined on the demand itself or the items delivery operation
If no delivery operation can be identified
  Flag the demand as unplannable

Set ask date = due date
Loop until the full demand quantity is planned
  Call solver of the delivery operation with arguments(missing quantity,ask date)

  If planned quantity = 0 then
    Call solver of the delivery operation with arguments(minimum delivery quantity,ask date)
      If the planned quantity is non-zero this time then
        Iteratively try to plan increasing quantities to find the maximum feasible quantity (bisection method)
  If planned quantity = requested quantity,
    Commit/accept the new operation plans
  else if the demand planning policy allows planning the demand in parts and remaining quantity would be less than the minimum then
    Rollback/refuse the new operation plans
    Remember the date and quantity (*)
  Else
    Rollback/refuse the new operation plans
  If planned quantity > 0 then
    // This step synchronizes all supplying paths for the quantity of the most constrained path
    Call solver of the delivery operation with arguments(planned quantity, ask date)
    Commit the operation plan creation

  Update the planned quantity for the next iteration in the loop
  Update the ask date for the next iteration in the loop, based on the reply date of the operation
  Exit the loop if the demand can’t be planned late

If the demand is not fully planned and there is a temporarily rejected plan from step (*) then
  Commit/accept the plan that was rejected before

    • Getting started
      • 1 – Introduction
      • 2 – Installation
      • 3 – Entering data
      • 4 – Modelling concepts
      • 5 – Your first model
      • 6 – Your first plan
    • Modeling guide
      • Simplified domain model
      • Detailed domain model
      • Environment variables
      • Python interpreter
      • Global parameters
      • Buffer
      • Calendar
      • Customer
      • Demand
      • Flow
      • Item
      • Load
      • Location
      • Operation
      • Suboperation
      • Operationplan
      • Problem
      • Resource
      • SetupMatrix
      • Skill
      • Resource skill
      • Solver
    • User guide
      • Supported browsers
      • Getting around
        • Logging in
        • Logging out
        • Changing password
        • Navigation
          • Menu bar
          • Jump search
          • Context menus
        • Filtering data
        • Sorting data
        • Selecting time buckets
        • Exporting data
        • Importing data
        • Customizing a screen
        • User preferences
        • User permissions and roles
        • Comments
        • History – Audit trail
      • Data maintenance screens
      • Supply Path / Where Used
      • Plan analysis screens
        • Problem report
        • Constraint report
        • Inventory report
        • Inventory detail report
        • Resource report
        • Resource Gantt report
        • Resource detail report
        • Operation report
        • Operation detail report
        • Demand report
        • Demand detail report
        • Demand Gantt report
        • Forecast report
        • Performance indicator report
      • Execution screen
      • Batch commands
        • frepplectl
        • frepple
        • freppleservice.exe (Windows only)
    • Installation guide
      • Windows installer
      • Compiling on Windows
      • Linux binary packages
      • Compiling on Linux
      • Compiling from the source code repository
      • Running the VMWare virtual machine
      • Other platforms
      • Configuring multiple models in the user interface
      • Configuring as a Python extension module
    • Extension modules
      • Forecast module
      • Order quoting module
      • REST web service module
      • OpenERP connector module
      • Linear programming solver module
    • Technical guide
      • Architecture
      • Source code repository
      • User interface
        • Creating an extension app
        • Translating the user interface
        • Adding or customizing a report
        • Style guide
      • Solver engine
        • Code structure
        • Class diagram
        • Planning algorithm
          • Top level loop
          • Demand solver
          • Buffer solver
          • Flow solver
          • Load solver
          • Operation solver
          • Resource solver
        • Cluster and level algorithm
        • Extension modules
        • Style guide
        • Portability
      • Security
      • Unit tests
        • buffer_procure_1
        • calendar
        • callback
        • cluster
        • constraints_combined_1
        • constraints_combined_2
        • constraints_leadtime_1
        • constraints_material_1
        • constraints_material_2
        • constraints_material_3
        • constraints_material_4
        • constraints_resource_1
        • constraints_resource_2
        • constraints_resource_3
        • constraints_resource_4
        • constraints_resource_5
        • datetime
        • deletion
        • demand_policy
        • flow_alternate_1
        • flow_alternate_2
        • flow_effective
        • forecast_1
        • forecast_2
        • forecast_3
        • forecast_4
        • forecast_5
        • forecast_6
        • jobshop
        • load_alternate
        • load_effective
        • lpsolver_1
        • multithreading
        • name
        • operation_alternate
        • operation_available
        • operation_effective
        • operation_pre_post
        • operation_routing
        • pegging
        • problems
        • python_1
        • python_2
        • python_3
        • safety_stock
        • sample_module
        • scalability_1
        • scalability_2
        • scalability_3
        • setup_1
        • setup_2
        • skill
        • xml
        • xml_remote
    • FAQ
    • License
      • GNU Affero General Public License
      • GNU Free Documentation License
    • Third party add-ons
  • Copyright © 2010-2013 frePPLe bvba