Production Plan Optimization for SMT Lines With Staged Integer Programming

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Solution Overview

Problem

In high-mix low-volume production lines, particularly in SMT lines, the complexity of optimizing production time is exacerbated by interdependent factors with trade-off relationships, leading to a combinatorial explosion of possible combinations, which increases processing load when generating production plans.

Innovation Solution

A production plan generation device and method that utilizes integer programming to optimize substrate group formation, component allocation, and manufacturing order, minimizing off-line setup waiting time and processing load by formulating and solving optimization problems for substrate group optimization, component allocation, and manufacturing order optimization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If comprehensive optimization of all factors affecting production time is performed, then production time is minimized, but processing load increases due to combinatorial explosion

Engineering Contradiction:
Improveproduction timeVSAvoidprocessing load
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent segments the production plan generation into distinct optimization stages: (1) substrate group formation optimization, (2) component allocation optimization, and (3) manufacturing order optimization. Each stage optimizes specific factors independently, avoiding the need to simultaneously optimize all factors together, thus reducing the combinatorial explosion while still achieving comprehensive optimization of production time.

Inventive Principle:
Principle #1Segmentation

2Loss of time

If substrate group formation is optimized to minimize production time, then trade-off relationships between mounting time and off-line setup time are addressed, but calculation complexity increases

Engineering Contradiction:
Improveproduction timeVSAvoidcalculation complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent divides substrate groups into multiple stages and optimizes each stage separately. The processor performs substrate group formation optimization by considering trade-off relationships between mounting time and off-line setup time for each group, then proceeds to component allocation and manufacturing order optimization in subsequent stages, reducing overall calculation complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary optimization of substrate group formation before proceeding to component allocation and manufacturing order optimization. By pre-determining optimal substrate groups based on trade-off relationships between mounting time and off-line setup time, the system reduces the search space for subsequent optimization stages, thereby reducing calculation complexity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3617821B1Production plan generation device, production plan generation program, and production plan generation method
Publication Date: 2023.03.29 FUJITSU LTD
  • EP3617821B1 patent drawingFigure 1
  • EP3617821B1 patent drawingFigure 2
  • EP3617821B1 patent drawingFigure 3

AI summary

In order to reduce the processing load when a production plan of a production line is generated, a substrate quantity information collector (30) and a production information collector (32) acquire substrate quantity information and production information, and a substrate group optimization unit (36), a component allocation optimization unit (38), and a production order optimization unit (40) optimize, in stages, multiple elements (substrate group, component allocation, substrate manufacturing order) that affect the time taken to complete production of a substrate, on the basis of the substrate quantity information and the production information.