Mumtaz Usmen

Improving university facilities services using Lean Six Sigma: a case study

Purpose – The purpose of this paper is to present a case study on the use of Lean Six Sigma principles and tools to study the improvement in design and construction services at a university. The quality of facilities services at universities has been criticized by users calling for improvement. Design/methodology/approach – Quality of facilities services at universities has been criticized by users calling for improvement. The purpose of this paper is to present a case study on using Lean Six Sigma principles and tools to study improving design and construction services at a university. Findings – It was found that non-value-added general improvement review form (GIRF) process steps involving revisions and rework for the design and construction result in time delays, cost increases and quality deficiencies and render cost estimates unreliable; these are unnecessary and should be minimized or eliminated. It was additionally noted that administrative reviews and approvals embedded in GIRF processes slow dow...

Modelling masonry crew productivity using two artificial neural network techniques

AbstractArtificial neural networks have been effectively used in various civil engineering fields, including construction management and labour productivity. In this study, the performance of the feed forward neural network (FFNN) was compared with radial basis neural network (RBNN) in modelling the productivity of masonry crews. A variety of input factors were incorporated and analysed. Mean absolute percentage error (MAPE) and correlation coefficient (R) were used to evaluate model performance. Research results indicated that the neural computing techniques could be successfully employed in modelling crew productivity. It was also found that successful models could be developed with different combinations of input factors, and several of the models which excluded one or more input factors turned out to be better than the baseline models. Based on the MAPE values obtained for the models, the RBNN technique was found to be better than the FFNN technique, although both slightly overestimated the masons’ pr...

Investigation of Factors Contributing to Fatal and Nonfatal Roofer Fall Accidents

Roofers continue to suffer frequent fall-related injuries and fatalities. The objectives of this research were (a) identifying the factors affecting roofer fall accidents; (b) investigating the frequency distributions of these factors; (c) examining the relationships between the factors; and (d) developing a statistical model for fatal and nonfatal fall outcomes. Occupational Safety & Health Administration (OSHA) accident data was analyzed using categorical variables. After establishing data demographics, cross-tabulation analysis was performed to determine factor relationships, and logistic regression modeling was done to predict accident outcomes using degree of injury as a dependent variable and the significant factors from cross-tabulation as independent variables. It was found that roofers most frequently experienced falls while working in smaller alteration/rehabilitation projects and at heights below 20 feet. Unguarded/improperly secured platforms, walkways, openings, edges and ladders, misjudgment of hazardous situation, and improper choice of equipment/process came out to be significant contributing factors. It was observed that the odds of fatality decreased when roofers were provided OSHA-compliant fall protection systems; used these systems; and received fall protection training per OSHA requirements. The model developed and validated in this study successfully predicted the fall accident outcomes in terms of fatality and nonfatal injury.

Evaluation of plastering crew performance in building projects using data envelopment analysis

AbstractThe research question addressed in this study was how the performance of construction crews working in a certain project or locality could be evaluated, ranked and improved. To develop and demonstrate the relevant framework, data envelopment analysis (DEA) was applied to establish the relative efficiency of plastering crews working in building projects located in different cities around Turkey. Data were collected from 40 crews of varying characteristics, and their technical efficiency scores were computed using the Banker, Charnes and Cooper (BCC) model, which is based on variable returns-to-scale (VRS). The model yields efficiency scores that range between 0 and 1, and a company or crew is considered efficient if its score is 1.0 (100%). Efficient and inefficient crews were identified and ranked on this basis in the study. Cross tabulation analyses were subsequently conducted to gain further insights into the relationships between the efficiency scores and input factors of numbers of skilled and...

İNŞAAT MÜHENDİSLİĞİNDE ETİK: AMERİKA BİRLEŞİK DEVLETLERİ ÖRNEĞİ

Insaat muhendisligi mesleginde faaliyet gosteren muhendislerin vermis oldugu kararlar toplum ve cevre sagligini ve ayni zamanda meslektaslarin, iscilerin, tesislerin guvenligini yakindan etkilemektedir. Bu yuzden, insaat muhendisleri verdikleri kararlarda cevreye ve topluma karsi sorumluluklarini dikkate almak ve meslek ahlaki kurallarina uymak zorundadir. Ayni zamanda etik olarak da bilinen meslek ahlaki kavrami ve kurallari calisma hayatinda karar verme yetkisine sahip kisilere, neyin dogru neyin yanlis oldugu konusunda yardimci olmayi amaclar. Bu konuda ulkemizde yazilmis olarak bulunan ve uygulanan kurallar ve yaptirim mekanizmasi bulunmamaktadir. Etik kavraminin onemini vurgulamak amaciyla, bu calismada etik konusunda temel olusturmus ve kurumlasmis Amerika Birlesik Devletleri (A.B.D.) ornek olarak alinmis ve yururlukte uygulamalar incelenmistir. Calismada etik kurallarin gelisimi, orgutlenme sureci ve etik ihlallerinde devreye giren yaptirim sistemi ve ornek etik vakalari ile etik inceleme kurulunun gorus ve yorumlari incelenmistir.

An Experimental Appraisal of the Load-Deformation Properties of A325 High-Strength Bolts

Current specifications and testing procedures of high-strength bolts are based on the results of early research performed in the late 1950s and the early 1960s using the testing technology available at that time. Within the past few decades, the development of new, advanced testing equipment and computerized data acquisition systems has brought about significantly improved capabilities for materials testing. In light of these advancements, conducting a new set of bolt tests was considered essential in appraising the load deformation properties of high-strength bolts using the new testing technology. In this study, samples of randomly obtained A325 high-strength bolts were tested in accordance with the ASTM standard test methods, utilizing a servo controlled universal testing machine and a computerized data acquisition system. This equipment differs from that used in the early research in the accuracy of the data collected and the existence of many available options for specimen loading. The new testing technology provides an easy determination of the yield point, the proof load, and ductility of the bolts. The study aimed at experimentally determining the load-deformation properties of high-strength bolts and comparing them with those generated by early research. The proof load, the yield strength, and the teasile strength obtained were much higher than the specified ASTM and AISC values. Additional studies were pursued to gain an improved understanding of the behavior of the bolts as affected by the exposed thread length in the grip. The tested bolts showed higher strength and lower ductility as the number of the thread exposed in the grip length decreased.