ESTIVATE: A model for calculating excavator productivity and output costs

David J. Edwards, Gary D. Holt

Research output: Contribution to journalReview articlepeer-review

40 Citations (Scopus)


Hydraulic excavator cycle time and associated unit costs of excavation for given input estimating data, for machines operating in the UK construction industry, are predicted. Using multiple regression analysis, three variables are identified as accurate predictors of cycle time: machine weight, digging depth and machine swing angle. With a coefficient of determination (R2) of 0.88, a mean percentage error (MPE) of −5.49, and a mean absolute error (MAPE) of 3.67, the cycle time model is robust; this is further validated using chi-square analysis and Pearson's correlation coefficient (on predicted and actual values of machine cycle time). An illustrative example of the model's application to determine machine productivity is given. The paper concludes with a spreadsheet model for calculating excavation costs (m3 and cost per h) which is able to deal with any combination of the three independent cycle time predictor variables and other estimator's input data.

Original languageEnglish
Pages (from-to)52-62
Number of pages11
JournalEngineering, Construction and Architectural Management
Issue number1
Publication statusPublished - 1 Jan 2000
Externally publishedYes


  • Construction plant
  • Cost estimation
  • Hydraulic excavators
  • Machine cycle time
  • Productivity

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Architecture
  • Building and Construction
  • General Business,Management and Accounting


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