Theophilus Adjei-Kumi

Management of Waste in the Building Design Process: The Ghanaian Consultants' Perspective

Waste associated with building design is one of the causes of the high cost and slow progress of construction projects in Ghana. Proper management of waste at the design stage is therefore a fundamental step towards achieving speedy delivery of building projects at minimum cost. This paper seeks to examine the level of awareness of sources of waste and the application of waste reduction tools in the building design process by Ghanaian consultancy firms. Data on the design activities of the firms were collected by distributing questionnaires to consultants, while contractors and clients were interviewed. Involvement in various building design processes was also used to obtain data for the study. Results revealed a generally low recognition of sources of waste in the building design process and little awareness of waste reduction tools such as design structure matrix, batch size reduction and set-based design. It was also found that inadequate familiarity of the firms with lean thinking was among a number of limitations to the application of waste reduction tools in Ghana. This suggests that there is a need to improve the awareness of lean design management in both education and practice in Ghana.

Exploring value for money (VfM) assessment methods of public-private partnership projects in Ghana

Purpose – The purpose of this paper is to explore the various approaches prescribed in literature in the assessment of value for money (VfM) of public–private partnership (PPP) projects with the aim to develop a theoretical framework for measuring VfM in Ghana.Public–private partnership (PPP) has long been recognized as an effective way of procuring public infrastructure to deliver value for money, but the subject has received little research attention in Ghana. Design/methodology/approach – The methodology comprises a multi-stage critical review of relevant literature; review of Ghana’s National Policy on PPP and review of the Public Procurement Act, 2003 (Act 663). This paper was underpinned by an interpretivist philosophy and is inductive in nature. Findings – The approach for VfM assessment largely depends on the jurisdiction of the project. Multiple methods (qualitative and quantitative) are used along the project cycle in the bid to achieve VfM. The most common assessment approaches include public sector comparator shadow bid, lease-purchase analysis, cost benefits analysis, public interest test central guidelines and competitive bidding. The study developed a theoretical framework for assessing VfM in Ghana. Research limitations/implications – The research was purely exploratory and non-empirical; and hence cannot be generalized in a broader context. Practical implications – Implementation of the National PPP policy and for PPP to thrive in Ghana, a framework to guide the assessment and achievement of VfM is crucial. The steps outlined if followed would help ensure the public receives the best of all PPP deals in Ghana. Originality/value – This paper is unique providing insights into a conceptual basis for assessing VfM and provides a basis for future empirical study.

Application of the CBA Decision System to Manage User Preferences in the Design Process

AbstractOne dimension of user-involvement in the design process is the management of user preferences. Managing user preferences, as a way towards optimizing value in the design process, could sometimes involve making tradeoffs among competing design options. The focus of this research is to explore the possibility of applying the choosing by advantages (CBA) decision system to manage user preferences in the design process, especially at the conceptual design stage. The CBA decision system was therefore applied to choose between two conceptual design options in relation to the expansion of an operating theater building at the Holy Family Hospital in Techiman, Ghana. A workshop involving the design team, user-group, and management of the hospital was organized to decide on the options using the CBA approach. The findings from this study illustrate the CBA decision aid as a transparent and participative decision system, capable of creating and sustaining a collaborative atmosphere of trust and respect in th...

An exploration of the choosing by advantages decision system as a user engagement tool in participatory design

ABSTRACT The significance of user involvement in design process towards generating value remains uncontested. It is however a challenge to identify the most appropriate strategy for engaging users to effectively participate in design process. This paper explores the suitability of the choosing by advantages (CBA) decision system for designers to engage users in design process. The paper specifically reports on a case application of CBA to make a typical design decision, such as the choice of a mode of operation of window openings, in the design of a three-storey lecture theatre at Takoradi Polytechnic in Takoradi, Ghana. A workshop, involving various stakeholders, including potential users of the project, was organized to apply CBA to choose among various modes of operation of window openings: louvres, sliding, awning, casement and pivoted. Findings, which were based on an active participation of a key member of the research team in the workshop, were further corroborated by direct observation and interview with some participants in the workshop. The findings point to CBA as a decision system capable of creating a collaborative forum for designers to engage users in design decisions.

Duration determination for rural roads using the principal component analysis and artificial neural network

Purpose Determining the duration for road construction projects represents a problem for construction professionals in Ghana. The purpose of this paper is to develop an artificial neural network (ANN) model for determining the duration for rural bituminous surfaced road projects. Design/methodology/approach Data for 22 completed bituminous surfaced road projects from the Department of Feeder Roads (rural road agency) were collected and analyzed using the principal component analysis (PCA) and ANN techniques. The data collected were final payment certificates which contained payment bill of quantities (BOQ) of work items executed for the selected completed road projects. The executed quantities in the BOQ were the total quantities of work items for site clearance, earthworks, in-situ concrete, reinforcement, formwork, gravel sub-base/base, bitumen, road line markings and furniture, length of road and actual durations for each of the completed projects. The PCA was first employed to reduce the data in order to identify a smaller number of variables (or significant quantities) that constitute 81.58 percent of the total variance of the collected data. The ANN was then used to develop the network using the identified significant quantities as input variables and the actual durations as output variables. Findings The coefficient of correlation (R) and determination (R2) as well as the mean absolute percentage error (MAPE) obtained show that construction professionals can use the developed ANN model for determining duration. The study shows that the best neural network is the multi-layer perceptron with a structure 3-38-1 based on a back propagation feed forward algorithm. The developed network produces good results with an MAPE of 17.56 percent or an average accuracy of 82.44 percent. Research limitations/implications Apart from the fact that the sample size was small, the developed model does not incorporate the implications of other likely factors that may affect contract duration. Practical implications The outcome of this study is to help construction professionals to fix realistic contract duration for road construction projects before signing a contract. Such realistic contract duration would help reduce time overruns as well as the payment of liquidated and ascertained damages by contractors for late completion. Originality/value This paper proposes an alternative way of determining the duration for road construction projects using the total quantities of work items in a final payment BOQ. The approach is based on the PCA and ANN model of quantities of work items of completed road projects.

Choosing By Advantages incorporated framework for a user-involved design process

ABSTRACT Participation of stakeholders, such as users, in the design process remains significant in generating value of construction projects. This calls for new approaches in the interactions between designers and users towards collaboratively understanding and meeting user needs. A systematic framework, incorporating the Choosing By Advantages (CBA) decision system is, therefore, proposed as a contribution to improving designer–user collaboration for value generation in construction projects. The framework, resulting from an action-oriented constructive research approach, is based on a combination of empirical knowledge from the case application of CBA on selected projects in Ghana, and relevant theory. It is structured along the Input-Mediator-Output-Input scheme of team process, containing six performance episodes connected with reciprocal dependency loops. Guided by the pragmatist stance on truth, the workability of the framework was evaluated in a case study. The paper contributes to design process management and stakeholder involvement by providing a systematic guide on employing a multi-attribute decision system for designers and users to collaboratively discover, generate and authenticate value at the design stage of construction projects.

Factors affecting tender price in the Ghanaian construction industry

Purpose Tender price remains an imperative parameter for clients in deciding whether to invest in a construction project, and it serves as a basis for tender price index (TPI) manipulations. This paper aims to examine the factors affecting tender price in the construction industry. Design/methodology/approach Based on the literature review, nine independent constructs and one dependent construct relating to tender pricing were identified. A structured questionnaire survey was conducted among quantity surveyors in Ghana. Partial least squares structural equation modelling (PLS-SEM) examined the influences of various constructs on tender price development (TPD) and the relationships among TPD and TPI. Findings Results showed that cultural attributes, client attributes, contractor attributes; contract procedures and procurement methods; consultant and design team; external factors and market conditions; project attributes; sustainable and technological attributes; and TPI have a positive influence on tender price, whereas fraudulent attributes exert a negative influence. Practical implications The findings offer construction professionals broader understanding of factors that affect tender pricing. The results may be used in professional decision-making in the pricing of construction projects, as they offer clearer causal relations between how each construct will influence pricing. Originality/value This study adds to the body of construction pricing knowledge by establishing the relationships and degree of influences of various factors on tender price. These findings provide a valuable reference for practitioners.

Participatory design, wicked problems, choosing by advantages

Purpose The phenomenon of wicked problems is inextricably associated with a design process, especially participatory design. The management of wicked problems in participatory design, however, remains largely unexplored. The purpose of this paper is to explore the use of the choosing by advantages (CBA) decision system to manage wicked problems in participatory design. Design/methodology/approach Two case studies, involving the application of CBA to make typical participatory design decisions, are evaluated to establish how responsively the CBA decision system operates in the midst of wicked problems in participatory design. Findings Findings point to the exploitability of some elements and attributes of the CBA process to manage wicked problems in participatory design, to some extent. The observed collaborative attributes of CBA is particularly helpful and play a key role in mitigating the adverse effects of wicked problems on collaboration in this regard. Practical implications The recommendation of the paper is the incorporation of CBA in the development of stakeholder involvement frameworks for a design process. Originality/value This paper contributes to knowledge on relying on elements and the attributes of a decision-making system, such as CBA, to manage stakeholder involvement in the design process, particularly focussing on wicked problems. The CBA decision system still remains emergent regarding its application and research in the AEC industry.

Rethinking the challenges to the pricing of projects in the Ghanaian construction industry

Purpose The aim of the paper is to examine the challenges to the pricing of construction projects in the Ghanaian industry. This remains a persistent problem among construction stakeholders because price is the basis for which offers are made. Project stakeholders are always faced with challenges relating to effective and efficient pricing system making it difficult to achieve value for money. Design/methodology/approach Research data were collected through a questionnaire survey involving quantity surveyors in the Ghanaian construction industry. Data collected were analyzed using exploratory factor analysis which helped to reduce the factors into six components. Confirmatory factor analysis (CFA) was further carried out to explore whether these six observed variables would form a latent variable called challenges to pricing of construction projects. Findings The paper highlighted six underlying challenges which were cost-related, managerial-related, quality-related, variation of works, poor understanding of the terms of contract and time-related. Strong and significant relationships were found between all six of the observed variables. A CFA confirmed that they formed a latent variable the authors called challenges to pricing of construction projects. Research limitations/implications The findings clearly can serve as a reference for both developed and developing countries in the quest for finding an antidote to pricing challenges. In addition, use of CFA improves measurement of the constructs and thus enhances understanding of the underlying components of a construct and their individual relationship with pricing. The paper is particularly useful for policy making and industry regulation because it identifies some of the factors that need attention. Originality/value This paper presents an exceptional contribution to the construction management literature by concentrating on the factors that challenge effective and efficient pricing system in the construction industry.

Duration estimation model for bridge construction projects in Ghana

Purpose A major concern for construction professionals at the rural road agency in Ghana is the problem of fixing contract duration for bridge construction projects in rural areas. The purpose of the study was to develop a tool for construction professionals to forecast duration for bridge projects. Design/methodology/approach In all, 100 questionnaires were distributed to professionals at the Department of Feeder Roads to ascertain their views on the work items in a bill of quantities (BOQ) that impact significantly on the duration of bridge construction projects. Historical data for 30 completed bridge projects were also collected from the same Department. The data collected were executed work items in BOQ and actual durations used in completing the works. The qualitative data were analysed using the relative importance index and the quantitative data, processed and analysed using both the stepwise regression method and artificial neural network (ANN) technique. Findings The identified predictors, namely, in-situ concrete, weight of prefabricated steel components, gravel sub-base and haulage of aggregates, used as independent variables resulted in the development of a regression model with a mean absolute percentage error (MAPE) of 25 per cent and an ANN model with a feed forward back propagation algorithm with an MAPE of 26 per cent at the validation stage. The study has shown that both regression and ANN models are appropriate for predicting the duration of a new bridge construction project. Research limitations/implications The predictors used in the developed models are limited to work items in BOQs only of completed bridge construction projects as well as the small sample size. Practical implications The study has developed a working tool for practitioners at the agency to forecast contract duration for bridge projects prior to its commencement. Originality value The study has quantified the relationship between the work items in BOQs and the duration of bridge construction projects using the stepwise regression method and the ANN techniques.