Methods and apparatus for the testing, monitoring and improvement of manufacturing process effectiveness

• US 5,617,321 A
• Filed: 12/22/1994
• Issued: 04/01/1997
• Est. Priority Date: 12/23/1993
• Status: Expired due to Fees

• Current Assignee: Comp Sci Holdings LLC (Intellectual Ventures LLC)
• Original Assignee: Computer Sciences Corporation (DXC Technology Company)
• Inventors: Jackson, Robert G., Frizelle, Gerald D. M., Woodcock, Eric J.
• Primary Examiner(s): Gordon, Paul P.
• Application Number:
  US08/362,263
• Time in Patent Office: 831 Days
• Field of Search: 364/148, 364/149, 364/150, 364/151, 364/401, 364/402, 364/468.1, 364/578, 395/54, 395/904
• US Class Current: 700/104
• CPC Class Codes: G05B 19/41885 characterised by modeling, simulation of the manufacturing system
• CPC Class Codes: G05B 2219/32015 Optimize, process management, optimize production line
• CPC Class Codes: G05B 2219/32338 Use new conditions for model, check, calculate if model meets objectives
• CPC Class Codes: G05B 2219/32356 For diagnostics
• CPC Class Codes: G05B 2219/32385 What is simulated, manufacturing process and compare results with real process
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y10S 706/904 Manufacturing or machine, e.g. agricultural machinery, machine tool

Abstract

Apparatus for optimising the design of a manufacturing process in order to achieve predetermined goals including: A computer simulation model of the structural elements of a manufacturing process pre-programmed to operate according to predetermined flow and sequencing rules and data describing the required product mix and to output, during operation, data on request relating to breakdowns and queues at various resources within the process. A calculator received the data and calculates first values of complexity and constituent elements thereof from the output data of the computer simulation model and second values of complexity and constituent elements thereof from similar data relating to the real manufacturing process in operation. A comparator for receiving and comparing the said first and second values and for selecting improvement data in accordance with the result of that comparison from an improvement rules database and for providing said improvement data to said computer simulation model so as to cause a modification of the model.

Claims

1. Apparatus for optimizing the design of a manufacturing process to achieve predetermined goals comprising;

a computer simulation model of structural elements of a manufacturing process pre-programmed to operate according to predetermined flow and sequence rules and data describing a required production process;

output means providing output data on request during operation relating to breakdowns and queues at various resources within said manufacturing process;

calculating means for calculating first values of complexity and consistent elements thereof from the output data of the computer simulation model and second values of complexity and consistent elements thereof from similar data relating to the real manufacturing process in operation;

comparing means for comparing said first and second values;

selecting means for selecting improvement data in accordance with the result of said comparison in said comparing means from an improvement rules database, said improvement data being provided to said computer simulation model to modify said simulation model according to said improvement data.

2. A method of improving the efficiency of a manufacturing process, comprising the steps of:

a) constructing a simulation model of a manufacturing process;

b) collecting relevant static dynamic, and control data from a real manufacturing process;

c) identifying and quantifying objectives;

d) calculating a first value of complexity of the process according to the formula for calculating the index of complexity H;

##EQU1## and said collected data;

e) calculating a second value of complexity of said manufacturing process according to said formula for calculating the index of complexity H;

f) comparing the difference between said first and second values of complexity with a predetermined difference limit;

g) modifying said simulation model according to whether said difference falls outside or inside said predetermined difference limit;

h) checking a validated simulation model against said identified and quantified objectives;

i) selecting an option from a predetermined hierarchial list of options;

j) modifying said simulation model with said selected options;

k) calculating values of complexity and consistent elements of the modified process simulation model using said formula for calculating the index of complexity H;

l) checking whether said identified and quantified objectives are met;

m) modifying said real manufacturing process in accordance with said modified simulation model.

3. The method according to claim 2 comprising continuously repeating said calculation of said second value of complexity of said manufacturing process and, comparing the difference between said first and second values, when said difference falls outside the limit of said predetermined difference limit.

4. The method according to claim 2 comprising continuously repeating said selection of an option from said predetermined hierarchical list of options using the calculated values of complexity and consistent element of the modified process from the formula for calculating the index of complexity H until said objectives are met.

5. The method according to claim 4 wherein said step of selecting an option comprises selecting an option from a list of control options or a list of simplification options.