The construction sector constitutes one of the most important sectors in the economy of any country. Contractor selection is a critical decision that is undertaken by client organisations and is central to the success of any construction project. For major construction projects, final contractor selection often follows the contractor selection stage. Contractor selection is a process which involves investigating, screening and determining whether candidate contractors have the technical and financial capability to be accepted to formally tender for construction work. The process should be conducted prior to the award of contract, characterized by many factors such as: contactor's skills, experience on similar projects, track- record in the industry, and financial stability. Several models and approaches have been developed to assist client organisations in the contractor selection decision making process. This thesis evaluates the current state of knowledge in relation to contractor selection models. The key features, strengths and limitations of each of these methods are critically evaluated. The key factors of particular interest to client organisations are assessed. This thesis reports on-going research which aims to develop improved contractor selection criteria and methods with specific application to make construction projects in the Libyan context. The aim of this thesis is to build a framework for contractor selection process in the Libyan Construction Industry (LCI) and to find out the major obstacles constraining its operations which so far have not yet been taken into account by the Libyan researchers. However, to address that, a huge investigation has taken place about the current statues for contractor selection in Libya, as well as, in developed and well developed countries. To achieve that, both, theoretical and empirical research was carried out between 2010 and 2013 in Libya. The theoretical study concentrated on the sector of construction industry (Cl) and its key issues, whereas the empirical study focused and explored on the Libyan Construction Industry (LCI) as the context for the study. Two case studies were utilized in this research. The case studies were used to provide more information about the current situation of the LCI and to identify the contractor selection procedures of construction projects in. Also, it assist the researcher to identify key research questions that can later be used in a questionnaire survey. This research was implemented through the administration of a questionnaire survey based on research questions that are required for the building of a framework for contractor selection procedure and the identification of the challenges and obstacles that are facing the clients in the selection process. The development of the framework includes, but is not limited to, contractor selection criteria, decision makers, consultant, clients and sub-contractor. Therefore, the data collection is based on responses from the public and private sector (clients, consultants, contractors and others that are involved in and are knowledgeable about the contractor selection process in the Libyan construction projects). Mean and analysis of variance (independent T-test) were used to manipulate the data from the questionnaire within the SPSS v.20 software environment. The resulting framework was subjected to a validation procedure which involved a structured Delphi technique process based on a focus group consisting of experts who were selected to help with validation of the framework and establishing the extent to which the framework is practical, clear, applicable and comprehensive. This research uses an integrated approach that combines AHP (Analytic Hierarchy Process) method and TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) method to evaluate and investigate the current existing practice of contractor selection in Libya. Also, the Delphi technique was used to establish a road map for contractor selection process. Twelve participants were selected to help with validation of the framework. Overall, this research found that the LCI was suffering from a total absence of contractor selection frameworks. This directly impacts on client satisfaction as well as government planning in the reconstruction of the country after the civil war in particular. To close this gap, this research was embarked upon to identify and explore the various contractor selection methods and frameworks that are utilized to support the guidance of contractor selection process toward success. As a consequence of this study, the Contractor Selection Process (CSP) is now very comprehensive and can now be a reference for any problem. Furthermore, this research will help decision makers and others involved to be more aware of and have a better understanding of the selection procedure in the LCI. This new understanding will help decision makers to make more efficacious decisions and to adopt good short and long term policies for contractor selection planning which can then be put into procedure. Even though this framework is built for the LCI, the research can be utilised in other countries that have a similar construction industry environment.

Interface management (IM) in its many forms (physical, contractual and organisational) has not received the management research it warrants in the construction sector. Offsite bathroom construction is seen as a sector of offsite construction that can aid the interface problems that are common in construction. However, interface problems that occur when using offsite bathrooms are considered to be as detrimental, if not more to the overall process when compared to traditional bathroom construction. This research will focus on organisational IM, through research into the relevant process and people factors required to mitigate potential IM problems in the offsite bathroom process. A literature review of IM, offsite construction and traditional construction was conducted which identified 16 factors that could have an influence on the organisational IM of offsite bathroom construction. A further literature review was carried out for each factor to establish its connectivity to the holistic process of the IM of offsite bathrooms. A proforma was constructed which gathered quantitative and qualitative data from 82 interviewees, associated with eight case study projects. The methodology adopted was based on the pragmatism philosophical stance, which concurs with a mixed method approach to the collection and analysis of the data. The quantitative data was analysed using frequency tables and the Wilcoxon sign rank test. The quantitative data was analysed using thematic analysis. The analysis identified nine of the 16 factors as main contributors to the IM of offsite bathroom construction. These nine factors consisted of six process factors: procurement, design management, supply chain management, health and safety, tolerance and quality. Three people factors were: communication, client/design team and the role of the project manager. A conceptual model was constructed to encapsulate each of the nine factors and their sub-factors. Important findings from the research identified the procurement route as both an enabler and a constraint, depending on its ability to allow early input from the main contractor and manufacturer to the uptake of offsite bathrooms. The cross-cutting importance of the people factors to the successful implementation of the process factors identified the importance of the main contractor maintaining supervision of the manufacturer and the interface problems created from incomplete design. Further analyses of all the findings identified communication and the role of the project manager as the two most influential factors, with early and informal communication and strong leadership from the project manager relevant to all factors that affect the successful IM of offsite bathroom construction.

Abstract Purpose: Contractors usage of inspection data for the purpose of experience feedback in order to improve the production processes is unusual. The usual procedure with the usage of inspection protocols is to use them as a tool for correcting building errors discovered at the time of the inspection. This report highlights the opportunities and challenges regarding a computer aided inspection process by studying what different people in the industry think about these issues. The aim of the study is to present a proposal on the structure of a program that handles inspection data in the purpose of experience feedback and statistics. The structure shows an example on how the information from inspection statements can be sorted. Method: The authors conducted a case study of a company that works with offsite construction. The data collection was performed through semi structured interviews at the company the study focuses on and also on another company in the same industry. To be able to conduct the interviews in a satisfying way the authors conducted a document analysis of previous inspection protocols as well as a literature study through which the authors became acquainted with the current research frontier. Findings: The data collection with following analysis, among other findings, resulted in that a digital inspection process would make the categorization of errors standardised which in turn would lead to better usage of the information provided from inspections. It was also found that companies within the industry wants to use a digital tool for experience feedback. Especially for, but not limited to, the ability to get statistics over what areas in the business that need improvement. The result most closely related to the aim of the study is the points the authors believe should be included in a specification for a digital tool, for managing inspection protocols and using them for experience feedback. These points are: minimal changes by hand, easy to navigate, the ability to keep statistics over inspection findings and the possibility to adapt the structure of the digital to the specific company or inspector. Implications: The core of the problem that the report intends to investigate is the weaknesses in how industrial contractors use the information from inspections. The result indicate that a digital tool may be part of the solution. With such a tool developed, with above mentioned points in mind, many of the reoccurring errors found through inspections would be made visible through the easy access of statistics. In this way companies that uses a tool like this would have an easier time to introduce changes in their operations to minimize errors. Limitations: The report is limited by the fact that it only targets companies that is working with offsite construction in an industrialized fashion and therefore only is privileged by their views of the issues. The inspectors, whom also would be affected by such a tool, is not included in this study. Keywords: ICT, experience feedback, offsite construction, inspection process, requirements engineering. Content is described in Swedish below. / Sammanfattning Syfte: Att industriella byggföretag använder sig av besiktningsprotokoll för erfarenhetsåterföring med syfte att förbättra produktionsprocessen är ovanligt. Det vanliga förfarandet handlar närmast om att använda protokollen enbart som åtgärdslistor för de fel som uppdagas vid besiktningstillfället. Denna rapport belyser möjligheter och utmaningar med en datorstödd besiktningsprocess genom att utreda vad olika personer i den industriella modulbyggbranschen tycker i dessa frågor. Arbetets mål är att presentera ett förslag på struktur för ett program som hanterar besiktningsanmärkningar för erfarenhetsåterföring. Strukturen ska visa hur informationen från besiktningsutlåtandena kan sorteras. Metod: Rapportförfattarna har utfört en fallstudie på ett företag inom industriellt modulbyggande. Datainsamlingen skedde genom semi-strukturerade intervjuer på företaget fallstudien fokuserar på och på ett annat företag i samma bransch. För att genomföra intervjuerna på ett bra sätt genomfördes en dokumentanalys av slut-besiktningsprotokoll från tidigare färdigställda projekt och det gjordes en litteratur-studie där rapportförfattarna bekantade sig med den nuvarande forskningsfronten i ämnet. Resultat: Sammantaget resulterade datainsamlingen, och analysen av denna, bland annat i att en digitaliserad besiktningsprocess hade kunnat göra kategoriseringen av fel standardiserad och att man då i högre grad kan utnyttja informationen i besiktnings-protokollen. Det visar sig också att de industriella byggföretagen i branschen vill använda sig av ett digitalt verktyg för erfarenhetsåterföring, framförallt men inte enbart för att få statistik över vilka områden i verksamheten som behöver förbättras. Det resultat som närmast svarar mot målet är de punkter som rapportförfattarna anser bör ingå i en kravspecifikation för ett digitalt verktyg för hantering av besiktningsprotokoll och erfarenhetsåterföring från dessa. Punkterna som rapportförfattarna kommer fram till är: minimal handpåläggning, lättnavigerat, möjlighet att föra statistik över besiktningsanmärkningar samt möjlighet att anpassa strukturen av det digitala verktyget utefter krav hos det specifika företaget eller besiktningsmannen. Konsekvenser: Kärnan i problemet som rapporten ämnar utreda är brister i hur industriella byggföretag i dagsläget använder sig av informationen i slut-besiktningsprotokoll. Rapportens resultat indikerar att ett digitalt verktyg kan vara en del i lösningen på problemet. Med ett sådant verktyg utvecklat efter ovan nämnda punkter som grund skulle många återkommande fel som idag upptäcks på slutbesiktningar synliggöras genom lättillgänglig statistik. På så sätt kan företag som använder ett sådant verktyg lättare införa förändringar i verksamheten för att minimera fel. Begränsningar: Rapporten begränsas i den mening att den endast riktar sig mot företag inom industriellt modulbyggande och då enbart deras åsikter i frågorna. Besiktningsmännen som också skulle påverkas av ett sådant verktyg ingår ej i studien. Nyckelord: ICT, erfarenhetsåterföring, industriellt byggande, besiktningsprocessen, requirements engineering.

<p>The United States presents the appropriate conditions for a wider adoption of offsite construction (OSC): steady growth in the construction industry, high construction wages, shortage of labors, and demand for housing – especially multifamily housing. The multifamily housing market is overheated, but many design and construction companies are still struggling to stay strong in this market, marked by tight profit margins, high competitiveness and inefficiencies. OSC presents itself as a solution to help design and construction companies to become more efficient and resilient to potential market crises. However, the architecture, engineering and construction (AEC) industry is hesitant to move to higher levels of OSC adoption, mainly because stakeholders, including owners, developers, designers, and construction companies, are not aware of the potential benefits resulting from OSC and are not prepared to promote the changes necessary for the successful adoption of OSC or for the engagement in modular construction, which would represent an important move towards industrialized construction. This study focused on how to implement strategic changes in design and construction companies, particularly small and medium-size enterprises, interested in successfully using OSC in multifamily housing projects, considering the need for more affordable and sustainable multifamily housing in the United States. Using mixed methods, the study involved five phases of data collection and data analysis and had the contribution of professionals from the AEC industry. Focusing only on the AEC industry of the United States, the researcher first identified the main factors affecting the use of OSC in multifamily projects, as well as the most important changes that design and construction companies need to adopt for the successful use of OSC in multifamily projects. The factors and the changes helped to structure and shape the scope of the principles, which were later consolidated and validated through research with professionals from design and construction companies. The final set of eight principles was divided into four topics: (1) strategy and business model, (2) people, organization, and culture, (3) technology, materials, and tools, and (4) processes and operations. In addition to helping to shape more efficient and resilient construction companies, the application of the proposed principles contributes to building more affordable and sustainable housing in the United States.</p>

<p>   </p> <p>The growing shortage of workers experienced in the labor-driven architecture, engineering, and construction (AEC) industry in the last decades has negatively impacted the industry, especially in the productivity. In the search of alternatives to alleviate this concerning situation, the AEC industry has readopted the concept of prefabrication (offsite construction). Compared to stick-built construction, offsite construction provides many advantages, such as construction in a controlled environment, the ability to perform parallel activities, quality improvement, less construction waste, safety improvement, and overall cost reduction. </p> <p>Despite the numerous advantages, there are challenges that have hindered the efficacy of offsite construction in practice. One of such challenges is the lack of interoperability in the design, planning, and construction workflows. Another challenge is that fabrication and assembly operations still rely on manual efforts which are time-consuming, costly, and error prone. With the advancement in digital and automation technologies, such as building information modeling (BIM) and robotics, there is an increasing interest in integrating these technologies to improve productivity in offsite construction. However, this has not been realized yet due to 1) the lack of BIM capability to incorporate automation technology in the design workflow, and 2) the lack of considerations of robotic technology to support AEC processes. </p> <p>Therefore, to address these gaps, in this research, the author proposed methods to 1) analyze building design information to infer construction-ready information and 2) generate construction operations simulations/animations using off-the-shelf robotic systems. The proposed methods consist of algorithms that enable: 1) inference of geometric and physical properties of building elements from industry foundation classes (IFC) models, and 2) generation of simulations for analyzing robot-assisted construction operations.</p> <p>These methods were tested on different test cases. Compared with manual efforts, the developed systems were more time efficient in the automated extraction of geometric and physical properties from IFC models as well as in the generation of the sub-module packages for constructability analysis using robotic automation. Experimental results showed that: (1) the developed method can be utilized in inferring the geometric and physical properties of building elements from IFC data models in an automated fashion, achieving 60.61% to 100% precision and 90.30% to 99.59% recall; and (2) the developed algorithms successfully generated the robot-related information from IFC-based BIM and successfully generated the simulation components automatically. Such automation reduces the needs of manual efforts in the extraction and generation of robotic simulation components. This research opens a new door for practitioners to analyze a building design related to the use of robotics for construction.</p> <p>  </p>