Underrun of required crane capacity - Losses of Productivity during reinforcing works

Christian Hofstadler*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference paper

Abstract

In terms of production logistics, cranes are one of the crucial equipment categories on the construction site; they are key pieces of equipment. They also play a major role as a link to both delivery and disposal logistics. Cranes are used for loading and unloading, moving and lifting of equipment and materials. The crane capacity is considered optimal if no delays occur for the individual members of the various teams working on the job site. However, delays and thus losses of productivity occur because many construction sites lack the minimum number of cranes required from a construction management point of view. Cranes are also crucial for reinforcing works. In an ideal setting, they move the reinforcing material to a position as close as possible to the location of assembly and laying. The reinforcement is usually delivered separately for each structural component and has a lead time of about one week in order to compensate for any variations in work performance or delivery times. Ideally, the reinforcement required soonest is put to interim storage (at a reinforcement storage space within reach of a crane) near the specific position of assembly and insertion in order to keep crane cycles as short as possible. Losses of productivity materialize if insufficient crane capacity is provided on the construction site. This paper uses a situation analysis to highlight the methods described in the literature to show changes in productivity in the event of an underrun of the required crane capacity. An expert survey served to gather data on how productivity decreases during reinforcing works if insufficient crane capacity is provided on the job site. Fifteen experts with extensive experience in costing, process planning, construction and claims management participated in this survey. A standardized questionnaire was used, and the experts were able to clarify issues with the interviewer. This approach enabled them to develop a better understanding of the survey, which resulted in more reliable data. The information collected in the expert survey is subjected to an exploratory analysis. Huber's M estimator method is applied to statistically represent the changes in labour consumption rates and productivity. These changes can be calculated very precisely using the derived equations, or determined graphically using diagrams.

Original languageEnglish
Title of host publicationISEC 2013 - 7th International Structural Engineering and Construction Conference
Subtitle of host publicationNew Developments in Structural Engineering and Construction
EditorsSiamak Yazdani, Amarjit Singh
PublisherResearch Publishing Services
Pages1349-1354
Number of pages6
ISBN (Electronic)9810753551, 9789810753559
DOIs
Publication statusPublished - 1 Jan 2013
Event7th International Structural Engineering and Construction Conference: New Developments in Structural Engineering and Construction, ISEC 2013 - Honolulu, United States
Duration: 18 Jun 201323 Jun 2013

Publication series

NameISEC 2013 - 7th International Structural Engineering and Construction Conference: New Developments in Structural Engineering and Construction

Conference

Conference7th International Structural Engineering and Construction Conference: New Developments in Structural Engineering and Construction, ISEC 2013
CountryUnited States
CityHonolulu
Period18/06/1323/06/13

Keywords

  • Construction process disruption
  • Expert survey
  • Insufficient crane capacity
  • Labour consumption rate
  • Loss of productivity
  • Productivity
  • Reinforcing works

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction

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