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DECISION SUPPORT MODEL FOR CONSTRUCTION CREW REASSIGNMENTS
Title
DECISION SUPPORT MODEL FOR CONSTRUCTION CREW REASSIGNMENTS.
Creator
Sist, Angela, Pet-Armacost, Julia, University of Central Florida
Abstract / Description
The reassignment of crews on a construction project in response to changes occurs on a frequent basis. The factors that affect the crew reassignment decision can be myriad and most are not known with certainty. This research addresses the need for a decision support model to assist construction managers with the crew reassignment problem. The model design makes use of certainty factors in a decision tree structure. The research helped to determine the elements in the decision tree, the...
Show moreThe reassignment of crews on a construction project in response to changes occurs on a frequent basis. The factors that affect the crew reassignment decision can be myriad and most are not known with certainty. This research addresses the need for a decision support model to assist construction managers with the crew reassignment problem. The model design makes use of certainty factors in a decision tree structure. The research helped to determine the elements in the decision tree, the appropriate combination rules to use with certainty factors, and the method for combining the certainty factors and costs to develop a measure of cost for each decision option. The research employed surveys, group meetings, and individual interviews of experienced construction managers and superintendents to investigate the current methods used by decision makers to identify and evaluate the key elements of the construction crew reassignment decision. The initial research indicated that the use of certainty factors was preferred over probabilities for representing uncertainties. Since certainty factors have not been used in a traditional decision tree context, a contribution of the research is the development and testing of techniques for combining certainty factors, durations, and costs in order to represent the uncertainty and to emulate the decision process of the experts interviewed. The developed model provides the decision maker with an estimate of the upper and lower bounds of costs for each crew reassignment option. The model was applied contemporaneously to six changes on three ongoing construction projects to test the model and assess its usefulness. The model provides a previously unavailable tool for the prospective identification and estimation of productivity losses and potential costs that emanate from changes. The users indicated the model process resulted in concise and complete compilations of the elements of the crew reassignment decision and that the model outputs were consistent with the users' expectations.
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Date Issued
2004
Identifier
CFE0000297, ucf:46212
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000297
INFLUENCE MAP METHODOLOGY FOR EVALUATING SYSTEMIC SAFETY ISSUES
Title
INFLUENCE MAP METHODOLOGY FOR EVALUATING SYSTEMIC SAFETY ISSUES.
Creator
Barth, Timothy, Pet-Armacost, Julia, University of Central Florida
Abstract / Description
"Raising the bar" in safety performance is a critical challenge for many organizations. Contributing factor taxonomies organize information on why accidents occur. Therefore, they are essential elements of accident investigations and safety reporting systems. Organizations must balance efforts to identify causes of specific accidents with efforts to evaluate systemic safety issues in order to become more proactive about improving safety. This research successfully addressed two problems: (1)...
Show more"Raising the bar" in safety performance is a critical challenge for many organizations. Contributing factor taxonomies organize information on why accidents occur. Therefore, they are essential elements of accident investigations and safety reporting systems. Organizations must balance efforts to identify causes of specific accidents with efforts to evaluate systemic safety issues in order to become more proactive about improving safety. This research successfully addressed two problems: (1) limited methods and metrics exist to support the design of effective taxonomies, and (2) influence relationships between contributing factors are not explicitly modeled within a taxonomy. The primary result of the taxonomic relationship modeling efforts was an innovative "dual role" contributing factor taxonomy with significant improvements in comprehensiveness and diagnosticity over existing taxonomies. The influence map methodology was the result of a unique graphical and analytical combination of the dual role taxonomy and influence relationship models. Influence maps were developed for several safety incidents at Kennedy Space Center. An independent assessment was conducted by a team of experts using the new dual role taxonomy and influence chain methodology to evaluate the accuracy and completeness of contributing factors identified during the formal incident investigations. One hundred and sixteen contributing factors were identified using the influence map methodology. Only 16% of these contributing factors were accurately identified with traditional tools, and over half of the 116 contributing factors were completely unaddressed by the findings and recommendations of the formal incident reports. The new methodology is being applied to improve spaceport operations and enhance designs of future NASA launch systems.
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Date Issued
2006
Identifier
CFE0001274, ucf:46928
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001274
DEFINING RISK ASSESSMENT CONFIDENCE LEVELS FOR USE IN PROJECT MANAGEMENT COMMUNICATIONS
Title
DEFINING RISK ASSESSMENT CONFIDENCE LEVELS FOR USE IN PROJECT MANAGEMENT COMMUNICATIONS.
Creator
Johnson, Gary, Pet-Armacost, Julia, University of Central Florida
Abstract / Description
A review of the literature regarding risk management and effective risk communications identified that very few researchers have addressed risk assessment confidence levels when using risk scoring methods. The focus of this research is to develop a definition of risk assessment confidence levels for use in internal project management communications and to evaluate its usefulness. This research defines risk assessment confidence level as "The degree of certainty that the likelihood or...
Show moreA review of the literature regarding risk management and effective risk communications identified that very few researchers have addressed risk assessment confidence levels when using risk scoring methods. The focus of this research is to develop a definition of risk assessment confidence levels for use in internal project management communications and to evaluate its usefulness. This research defines risk assessment confidence level as "The degree of certainty that the likelihood or consequence score (assigned by the risk assessor) reflects reality." A specific level of confidence is defined based on the types of analyses that were conducted to determine the risk score. A survey method was used to obtain data from a representative sample of risk assessment professionals from industry and academia to measure their opinion on the usefulness of the defined risk assessment confidence levels. The survey consisted of seven questions related to usefulness--four questions addressed the importance of stating confidence levels in risk assessments and three addressed the usableness of the proposed confidence level. Data were collected on the role and experience level of each of the respondents and the survey also included a comment section to obtain additional feedback. The survey generated 364 respondents representing a broad variety of roles associated with decision making and risk management with experience levels from fairly new to experienced risk assessors. The survey data were analyzed by calculating the proportion of respondents who gave negative, neutral and positive responses to the survey questions. An examination of the roles of the survey respondents indicated that no single group was dominant. A non-parametric Kruskal-Wallis test generally failed to reject the hypothesis that the means of the survey response distributions were identical. There was one exception which indicated that there are differences based on role and by inspection of the responses, it appears that decision makers, academics, and others more strongly support the need for confidence level information to reduce the difficulty in making risk based decisions in projects. The survey responses at a confidence level of 95% have a range of errors from 3.84 to 4.97%. Based on the results of the survey, 77 – 83% of those surveyed indicated agreement that knowing the confidence the assessors have in their assessment is important and would improve a management decision. The survey showed that 60 – 86% of the respondents agreed that the confidence levels and their definitions as presented in the survey were usable. The question with the lowest agreement (60%) was related to the way in which the individual levels were defined. The ad-hoc comments provided in the survey were divided into eleven groups based on similarity of the subject of the comment and then examined for common themes. These added additional insight into the results and useful information for future research efforts. This research validates that the use of risk assessment confidence levels is considered to be useful in project risk management. The research also identified several potential areas for future work, including determining the appropriate number of confidence levels that should be defined, refining the definition of the individual confidence level definitions, examining historical perspectives of whether the risk assessments were accurate, examining the concept of shiftability of risk assessments, further research on communication of variability of risk assessments, and research into the usefulness of risk matrices.
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Date Issued
2008
Identifier
CFE0002352, ucf:47791
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0002352