The Impact of Change Orders on Electrical Construction Labor Efficiency PDF Download

Author: David John Thomack
Publisher:
ISBN:
Category : Construction industry
Languages : en
Pages : 204

View

Book Description

Author: Matthew J. Bruggink
Publisher:
ISBN:
Category : Construction industry
Languages : en
Pages : 352

View

Book Description

Author: Paul Joseph Vandenberg
Publisher:
ISBN:
Category : Construction industry
Languages : en
Pages : 236

View

Book Description
Change orders impact many areas of construction projects. However, the impacts that change orders have on labor efficiency are much harder to quantify and are, therefore, a significant risk to contractors. Little research has been completed in the past quantifying these impacts so that disputes are common between owners and contractors regarding the actual cost of change. This study uses data from 43 projects, 27 impacted by changes and 16 not impacted by changes, to develop a linear regression model that predicts the impact on labor efficiency. The input factors needed for the model are: (1) Total Actual Project Hours, (2) Total Estimated Change Hours, (3) Impact Classification, and (4) Timing of Change. Timing of Change is calculated by breaking the project schedule down into six periods (i.e., changes before construction start, 0 - 20%, 20 - 40%, 40 - 60%A, 60 - 80%, and 80 - 100%), listing the percentage of change that occurred in each period, and calculating a weighted timing factor. The model calculates the labor loss or gain in efficiency for a particular project so that owners and contractors will better understand the true change impact on labor efficiency. Significant results have been found in hypothesis testing. The results show that impacted projects have larger amounts of change, have a larger decrease in labor efficiency, and are more impacted by change that occurs later in the project schedule. These results appear to be consistent with the intuitive judgement of industry professionals. The research is limited to the mechanical trade, but does include specific work in plumbing, HVAC, process piping, and fire protection.

Author: Joel Phillip Dettwiler
Publisher:
ISBN:
Category :
Languages : en
Pages : 104

View

Book Description

Author: Pehr Anthony Peterson
Publisher:
ISBN:
Category :
Languages : en
Pages : 350

View

Book Description

Author: Kenneth Timothy Sullivan
Publisher:
ISBN:
Category :
Languages : en
Pages : 542

View

Book Description

Author: Timothy W. Gotzion
Publisher:
ISBN:
Category :
Languages : en
Pages : 288

View

Book Description

Author: Michael T. Callahan
Publisher: Wolters Kluwer
ISBN: 0735552371
Category : Law
Languages : en
Pages : 628

View

Book Description
Construction Change Order Claims brings you up-to-date with the latest methods for determining value of work or all types of projects. Commonly encountered claim issues are covered in detail, including: Surety issues Evaluating changes resulting from ambiguous specifications or inadequate design Measuring the cost impact of delays Proving the price of damages This all-in-one resource guides you through every type and aspect of change claims, offering hands-on guidance and analysis from 25 experienced practitioners. Construction Change Order Claims helps you quickly answer difficult questions such as: Is a change order on a construction project an and“extraand”and—or is it included within the scope of the basic contract price? When does an ownerand’s unintentional interference cross the line between a mere impairment or hindrance to an alteration of the contractorand’s intended methods of performance? What specific circumstances support the use of the cardinal change doctrine? What circumstances must be present to employ the Percentage of Completion accounting method? Construction Change Order Claims delivers: Innovative defenses to avoid being bound by a release Guidance for anticipating contractor defenses, and for preparing opposing arguments Practical tips and accounting tools for evaluating progress and calculating payments Federal, state and local certification requirements for public and private projects And more!

Author: Karim Ashraf Sabry Iskander
Publisher:
ISBN:
Category :
Languages : en
Pages : 149

View

Book Description
Change orders occur in almost every construction project and regularly cause variations to the contractors' anticipated working conditions, resources, and manner of work completion. Change orders are major source of additional congestion, change in sequence, and loss of momentum in the construction jobsite. They frequently cause unforeseen labor productivity loss, which forces contractors to extend their stays on projects. Contractors encounter a lot of resistance from owners when proving productivity loss attributable to change orders, which may lead to unresolved disputes and lengthy litigations. Previous researchers attempted to set standards and methods in order to quantify the cumulative impact of changes on labor productivity. Some of the previous studies were based on case studies of two or three projects, others included a larger number of projects and more reliable analysis. Generally, it is very difficult to conclusively determine the exact amount of productivity loss attributable to change orders. As a result, there is a continuous need to enhance and enrich the cumulative impact research field. This current research is based on a database of one hundred and forty-five mechanical and electrical projects, encompassing two project groups: projects impacted by changes, and projects unimpacted by changes. Using two-sample t-tests and Chi-squared tests, a series of numerical and categorical variables were found to be significant in distinguishing between impacted and unimpacted projects, thus revealing the underlying causes of productivity loss associated with change orders. Furthermore, sixty-eight impacted projects were used in order to quantify the cumulative impact of changes using linear regression analysis. A series of statistical model selection criteria were applied in order to carefully identify the best predictive models. Candidate models were statistically diagnosed and thoroughly tested to check their validity. Statistical tests and measures were used in order to check whether there are outlying or influential observations in the models. In addition to that, new projects were collected to verify the future predictive ability of the candidate models. The analysis identified the following six factors as best cumulative impact predictors: percent owner initiated change orders, overmanning, turnover, absenteeism, percent time spent by project manager on project, and productivity tracking. The models developed in this research provide the construction industry with means that could be used during dispute resolutions to support the contractors' calculations and assertions for cumulative impact claims. Finally, this study incorporates a significant statistical component that highlights the most common challenges that analysts face when building linear regression models, such as multicollinearity and the presence of hidden extrapolations. The models developed in this research were extensively analyzed in full details through various statistical tests and measures in order to avoid misleading and deceptive results.

Author: Eddy M. Rojas
Publisher: J. Ross Publishing
ISBN: 1604270004
Category : Technology & Engineering
Languages : en
Pages : 344

View

Book Description
Presents construction productivity concepts. This book includes topics such as measuring labor productivity, establishing a field benchmarking program, negotiating loss of labor efficiency, and recommended practices for productivity enhancement. It is suitable for electrical engineers and students.