Scheduling Logic in an APS-System

An optimal planning result cannot be obtained through simple forward or backward scheduling. Requirements for production optimization are complex, including many factors such as: bottleneck processes, load leveling, sequence optimization, order prioritization, as well as an optimal ratio of make-to-order to make-to-stock production, and many more.

The best possible schedule for your factory can only be realized through a scheduling logic that is tailored to your specific circumstances. Asprova provides customizable scheduling parameters and rules for complete and highly detailed mapping of every single production facility and resource.

Aspects of the logic that are relevant to scheduling of individual resources and the factory as a whole include:

  • Dispatching Rules: prioritization rules for order assignment
  • Resource Evaluation: resource selection rules
  • Planning strategy: individual planning steps combined into what is the final scheduling logic
  • The dispatching rule is an order and process sequence sorting rule.
  • In other words: Orders and individual processes thereof are scheduled according to a variety of set dispatching keys, which include priority, delivery date, technological parameters, ABC-customers, customer order positions, and many more.

Asprova determines optimal resources for production according to set rules. They are chosen according to factors such as load levelling, setup time minimization, waiting time, order delays, inventory reduction, and many more.

  • Optimal scheduling results that reflect a complex factory are impossible to achieve through purely mathematical optimization. 
  • In order to obtain the best scheduling results possible, a completely customized scheduling logic is created that Asprova runs through step-by-step.
  • The scheduling logic model is created during the implementation phase with our assistance, though with growing knowledge on your side you become able to further fine-tune it.
  • The entire schedulign logic is initialized with the press of a butten. For this reason, Asprova is called "fully automatic".
  • The following is an example of several successive plannign steps, that would commence with the press of a button:
    1. Import production feedback and update the schedule.
    2. Import new orders and update the schedule.
    3. Schedule all production orders forward (to minimize capacity).
    4. In the case of delay, split order quantities across alternative resources (where applicable).
    5. If, during forward scheduling, an order is completed more than three days early, initiate backward scheduling from the due date for that order.
    6. Compress other orders that are excluded from backward scheduling (to fully utilize resource capacity).
    7. Schedule upstream processes backwards with regard to the bottleneck process (to avoid push-production and shorten lead time).
    8. Optimize the order sequence on bottleneck resource(s), in order to reduce changeover times (and boost production capacity thereon).
    9. Level out resource load before bottleneck process(es).

Asprova distributes processes evenly across fitting resources, in order to level out overall resource load.

  • Bottleneck scheduling consists of the combined use of the pull- and push principle.
  • The production tact is determined by the bottleneck process; upstream and downstream processes are scheduled around it.
  • This leads to a minimization in waiting times before and after bottleneck processes and thus also in total lead time.
  • The optimization logic feature of Asprova allows for optimization for order sequence optimization within set periods of time according to:
    • Setup Time Minimization
    • Resource Load Levelling
  • Examples of changeover time optimization:
    • Painting and coating systems: sorting from light to increasingly dark colors
    • Sheet metal manufactuing: sorting from thin to increasingly thicker sheets
    • Heat treatment: sorting from high to low temperatures
  • Examples of a set optimization time period (merge period):
    • Painting and coating systems: Orders within a time period of four hours are put together and the order sequence thereof starts with light colors that become increasingly darker.
    • Heat treatment: Orders within a time period of three days are put together and the order sequence thereof starts with high temperatures that become decrease with each order.