Order approval is the link between machine utilization planning as the last phase of production process planning and the activities within the production control system. Although the flow of production in terms of quantity and timing is predetermined within the production planning system, prior to the implementation of the orders by the order release, it must be checked whether the required resources (preliminary products, materials, tools, operating resources, NC programs and workers) are actually available. With regard to the release algorithm, a distinction is made between static and dynamic order release.
With the static order release, the availability check of the resources is aligned with the time of the order release. An order is therefore only released if the required resources are physically available at the time of release.
Dynamic order release requires a simulation of the production process and also releases those orders whose required preliminary products are not physically available at the time of the availability check, but will be completed by the planned start date based on the production simulation.
The load-oriented order release, which has already been implemented in PPS standard software (production planning and control systems), has established itself as a special characteristic of the static process. With this method, only as many orders (measured in production hours) are released into production as can be processed by it, taking into account a disposition limit to compensate for disruptions and incorrect estimates. In this way, a reduction in the costs of tied up capital is achieved by reducing the stocks in production.