Work Assistance Device Setup Order Optimization

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Solution Overview

Problem

Determining the optimal execution order for setup work in production lines with multiple apparatuses is complex and prone to combinatorial explosions as the number of production lines increases, leading to increased computational complexity and potential calculation stoppages.

Innovation Solution

A work assistance device and method that utilize a server-connected production system, employing integer programming to determine the setup work order by managing production time data and using a threshold-based approach to reduce the number of variables, thereby minimizing computational complexity and preventing combinatorial explosions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of production lines or apparatuses increases, then the productivity increases, but the computational complexity increases leading to combinatorial explosion

Engineering Contradiction:
Improveproduction capacityVSAvoidcomputational complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the calculation process into two distinct phases: a first calculation that determines setup work orders using production start/end times and setup times, and a second calculation that determines production start times based on the established setup orders. This segmentation divides the complex combinatorial optimization problem into manageable sequential steps, avoiding the need to simultaneously optimize all variables and thus preventing combinatorial explosion while maintaining the ability to handle multiple production lines

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary calculation of setup work orders before determining production start times. By first establishing the optimal setup sequence based on available production time windows and setup durations, the system prepares the foundation for subsequent production scheduling. This preliminary action reduces the complexity of the second calculation stage, as the setup orders are already determined and can be used as fixed inputs for production timing optimization

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3451093B1Work assistance device, work assistance method, and work assistance program
Publication Date: 2019.10.09 FUJITSU LTD
  • EP3451093B1 patent drawingFigure 1
  • EP3451093B1 patent drawingFigure 2
  • EP3451093B1 patent drawingFigure 3

AI summary

An integer programming problem generation unit 38 acquires, from a production plan information DB 52, production plan information related to figure numbers for which setup work is yet to be performed, and formulates, as an integer programming problem, on the basis of the acquired production plan information, and predetermined restrictions, a problem for optimizing the execution order of the setup work. An integer programming problem solver unit 40 uses GLPK or the like to determine the execution order of the setup work for each figure number. In this case, the integer programming problem generation unit 38 calculates, on the basis of the production plan information, a temporary setup work start time Si for each figure number of each mounter line, and, if the difference between Sj of figure number j and Si of figure number i which belongs to a different mounter line is equal to or greater than a threshold value DT, sets the setup order relationship between figure number i and figure number j to the order i→j. Accordingly, an appropriate execution order for the setup work can be determined with little computational complexity.