PREDICTION SHOVEL - TRUCK PRODUCTION: A RECONCILIATION OF COMPUTER AND CONVENTIONAL ESTIMATES

EARTH MOVING PRODUCTION FROM A SHOVEL AND ITS ASSOCIATED TRUCK: A TWO-LENGTH SYSTEM WITH ONE CARRIER AND ONE OF THE LENGTHS, IS DISCUSSED. THE OUTPUT IS ANALYZED OF MANY COMPUTER SIMILATION RUNS AND THE RESULTS RECONCILED WITH CONVENTIONAL ESTIMATES FOR SHOVEL-TRUCK PRODUCTION. THE STANFORD TWO-LENGTH SIMULATION MODEL IS A VALUABLE AND ECONOMICAL TOOL FOR STUDYING THE BEHAVIOR OF THE SHOVEL-TRUCK SPREAD. THE SIMULATION MODEL CAN BE APPLIED TO THE FOLLOWING PROBLEMS OF THE EARTH MOVING CONTRACTOR: (1) THE PROPER SIZING OF TRUCKS TO A SHOVEL, (2) THE DETERMINATION OF THE BEST NUMBER OF TRUCKS TO USE FOR A GIVEN HAUL DISTANCE, (3) DETERMINATION OF THE EFFECTS OF CHANGING DIFFERENT PARAMETERS, SUCH AS EXTERNAL DELAY TIMES, PROBABILITIES OF DELAY (EFFECT OF PREVENTIVE MAINTENANCE), AND MANY OTHERS, (4) DETERMINATION OF THE EFFECT OF USING A HOPPER AT THE SHOVEL, (5) PREDICTION OF PRODUCTION FOR USE IN ESTIMATING A JOB, (6) PREDICTION OF PRODUCTION IN ORDER TO DETERMINE ACTUAL OUTPUT ON A JOB ALREADY IN PROGRESS. FOR THE SHOVEL-TRUCK SPREAD WITH AVERAGE PROPERTIES, THE USE OF THE D-FACTOR TO ADJUST THE CONVENTIONAL ESTIMATE WAS DEMONSTRATED. HOWEVER, THE D-FACTOR MUST BE USED WITH CAUTION IN SYSTEMS WITH UNUSUAL PROPERTIES SUCH AS A HIGH COEFFICIENT OF VARIATION OF CYCLE ELEMENT TIMES. IT WAS FOUND THAT THE FOLLOWING PARAMETER SHOULD BE RECORDED FOR EACH JOB AND USED TO CHECK ON THE ORIGINAL ESTIMATE OF PRODUCTION: (1) COEFFCIENTS OF VARIATION OF EXTERNAL DELAYS FOR SHOVEL AND TRUCK, (2) RATIO OF MEAN TO MINIMUM VALUE OF LOG NORMAL DISTRIBUTIONS, (3) EFFICIENCY OF SHOVEL CYCLE AND TRUCK TRANSIT CYCLE BASED ON EXTERNAL DELAYS, AND (4) THE AVERAGE EXTERNAL DELAY TIMES FOR SHOVEL AND TRUCKS. THE CYCLE TIME EVALUATION SHOWED THAT THE LOG NORMAL DISTRIBUTION BEST DESCRIBES THE PROBABILITY OF CYCLE ELEMENT TIMES. FOR THE SHOVEL-TRUCK SYSTEM, TWO SIMPLIFIED METHODS FOR ACHIEVING SIMULATION RESULTS WERE OFFERED. SUPPLEMENT NO. 1 OF THE REPORT PRESENTS THE FORTRAN IV TRANSLATION OF THE BALGOL PROGRAM.

  • Supplemental Notes:
    • Tr No 37, SUPPL NO 1, 67 PP & SUPPL 26 PP, 6 FIG, 5 TAB,
  • Corporate Authors:

    Stanford University

    Stanford, CA  USA  94305
  • Authors:
    • DOUGLAS, J
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00215268
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 3 1970 12:00AM