Method and apparatus for assigning assemblies to component fitting lines
AssigneeSiemens Aktiengesellschaft
InventorsAlexander Pfaffinger, Christian Royer
Life of this patent
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Abstract
Provided is a method for allocating assemblies to placement lines for placing components on the assemblies, in order to achieve a minimum variation in components with a predefinable maximum capacity utilization in terms of time for each placement line, wherein the component variation is determined as the sum of the number of component types required on the placement lines and an expected production time is determined for each assembly type of the assemblies to be provided with components and for each placement line, taking into consideration each cycle time for the assembly type on the placement line, each reset time, the degree of utilization for each line and the expected number of pieces to be produced for each assembly type.
Claims18
A method for assigning assemblies to component fitting lines for fitting the assemblies with components in order to achieve a minimal component variance for prescribed maximum utilization levels over time per component fitting line, wherein the component variance is determined as a sum of a number of component types needed on the component fitting lines, wherein an expected production time is ascertained for each assembly type of the assemblies to be fitted with components and each component fitting line taking into consideration a respective cycle time for the assembly type on the component fitting line, respective conversion times, a respective level of line use and an expected number of items to be produced per assembly type,
- wherein an actual number of items to be produced arises according to a previously determinable probability distribution,
- wherein a sum of these expected total production times must not exceed the maximum utilization level of the respective component fitting line over time for the set of assemblies that is assigned to a line,
- wherein possible assignments of assemblies to the component fitting lines are limited by existing infrastructure or by user-defined presets,
- wherein the assignment is made such that for the probability distributions for a sum of the expected production times per component fitting line that result from the probability distributions, the differences from the respective expected value of these resultant probability distributions are limited by a prescribable maximum difference,
- wherein the assignment of the assemblies to the component fitting lines is computed for the given presets by integer linear programming.
An apparatus for assigning assemblies to component fitting lines for fitting the assemblies with components, having:
- a unit for ascertaining an expected production time for each assembly type of the assemblies to be fitted with components and for each component fitting line taking into consideration a respective cycle time for the assembly type on the component fitting line and an expected number of items to be produced per assembly type, wherein an actual number of items to be produced can arise according to a previously determinable probability distribution, wherein a sum of these expected total production times must not exceed the maximum utilization level of the respective component fitting line over time for a set of assemblies that is assigned to a line, wherein possible assignments of assemblies to component fitting lines can be limited by existing infrastructure and/or by user-defined presets and wherein a component variance is determinable as a sum of a number of component types needed on the component fitting lines in order to achieve a minimum component variance for prescribed maximum utilization levels over time per component fitting line, and
- a unit for computing the assignment of the assemblies to the component fitting lines for the given presets by means of integer linear programming, wherein the computation of the assignment is effected such that for the probability distributions for a sum of expected production times per component fitting line that result from the probability distributions, the differences from the respective expected value of these resultant probability distributions are limitable by a prescribable maximum difference.
Dependencies are inferred from the claim text.