136 research outputs found

    Gemba kaizen model based on BPMN for small and medium scale construction businesses in Nigeria

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    This paper is a demonstration of how Gemba kaizen which is continuous improvement in the workplace can be implemented using business process modelling and notation (BPMN). The scope of the study is construction businesses in the Nigeria. In developing the BPMN model for construction businesses in Nigeria, the modus operandi regarding decision making and managing challenges which may be transferred to the cost planning were identified. The mixed method approach was used to develop this model from the qualitative and quantitative findings. The survey strategy was employed for the analysis covering eleven interviews and one hundred and thirty-five questionnaires from contractors, cost and project managers in small and medium scale companies in Lagos, Nigeria. NVIVO 10 and descriptive statistics were used to assess the results. The findings of the study focused on the perception towards change, post-project reviews, openness to new ideas and innovation. The study observed post-project reviews as the only significant indicator of continuous improvement in Nigerian small and medium scale construction companies. This result is not enough to indicate that there is continuous improvement. Therefore, the model design focused on continuous improvement activities for the companies. The creation of a BPM model elucidated the continuous improvement functions, stages and processes. This study may be implemented in construction companies around developing economies for improving the competitive advantage of small and medium scale construction companies

    Continuous improvement framework using IDEF0 for post-contract cost control

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    Advancements in construction project management have necessitated a comprehensive rethink of construction project processes. Gantt charts and critical path analysis have been produced to create a work breakdown structure which can identify challenges and crucial infrastructure development activities which can have an adverse impact on the project. However, they do not improve the construction process. Integration DEFinition Language 0 (IDEF0) models, presents an opportunity for construction project managers to identify essential workflows during construction and improve them. The improvement process is continuous. Hence, kaizen which is part of lean construction can be implemented. This study demonstrated the use of IDEF0 in a building construction project in Nigeria where the construction companies have issues with cost, overruns, low competitive advantage and unsatisfied clients. The build up to the challenges identified post-contract cost controlling techniques as an important variable in establishing the challenges above in the construction industry. With the aid of Kendall’s coefficient of concordance, the analysis was carried out to determine the techniques which are most important and effective in managing construction cost during the execution phase. Monitoring building material cost was identified to be the most important technique. The recognised significant and effective techniques were used to build a continuous improvement model with accompanied drivers such as the working budget and monitoring of overhead. The output of the findings was presented in an IDEF0 models with some written guidelines. The model designed in this study can be used on construction sites by cost and project managers to reduce and maintain current costs from the working budget through continuous improvement

    The need for kaizen costing in indigenous Nigerian construction firms.

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    The application of adequate cost management methods and techniques before and during construction activities is a major determinant of project success. Construction cost management methods such as target costing, life cycle costing, activity based costing and kaizen costing are some of the ways in which a project cost can be effectively managed. Kaizen is a Japanese word for continuous improvement and it has been used in the Japanese manufacturing sector since the 1960s. This method employs techniques for incremental cost reduction and it is based on Kaizen philosophy and principles. Kaizen costing is a very useful method for post-contract cost control because it is applied during the manufacturing or production stage of a product. This cost control method creates more profit for the manufacturer, provides better quality products and improves customer satisfaction. Kaizen costing is a post-contract cost management method which can be used to increase the competitiveness of a company. This approach can be combined with target costing and other cost management methods for more effectiveness. This paper focuses on how kaizen costing can be used as a means of overcoming the challenges facing the Nigerian construction firms in terms of cost overrun; project delays and abandonment; inadequate cost control management and improving competitiveness of indigenous construction firms. Based on existing literature, this paper illustrates how kaizen costing can effective contain the challenge of cost and time overrun during construction

    Positioning cost overrun research in the philosophical debate: a case for critical realism.

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    Construction management research, as a form of social research is confronted with the fundamental paradigmic dilemma of determining a core philosophical orientation, to be considered adequate and best suited to enquiry about construction phenomena. The underpinning argument being that, the differences in world views, will yield marked differences in the type of knowledge generated. An empirical profiling of cost overrun research reveals the predominance of mono-method studies based on questionnaire survey methods, correlative analysis and archival data modelling techniques, all of which are underlain by positivism. Such positivist philosophies, although methodologically valid, cannot adequately explain and provide in-depth understanding of the contextual drivers in construction organisations that trigger the more tangible technical constructs leading to the phenomena of cost growth in projects. Joining in the chorus call for methodological pluralism in construction industry research, this study makes a case for critical realism specifically in the context of cost overrun research

    Morphological Survey of the Fruits of the Cultivated (Solanum Lycopersicum Linn.) and Wild (Solanum Pimpinellifolium Miller) Tomatoes in Ile-Ife, Nigeria

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    The last few years have recorded an increase in the forms of the cultivated tomato fruits available in Ile-Ife, Osun State, Nigeria. The morphological survey of the fruits of the cultivated garden tomato Solanum lycopersicum Linn. and its wild relative, Solanum pimpinellifolium Miller was carried out with the aim of documenting the various forms available on the basis of their different shapes and sizes. The qualitative morphological characters observed were, fruit colour and shape while the quantitative data taken were, the number of ribs present on the fruits, length and diameter of fruits. In this study, thirty-one (31) fruit forms were reported for the cultivated species based on the differences in shapes, presence or absence of ribs on fruits, number of ribs and colour of fruits. The shapes observed in Solanum lycopersicum were ellipsoid, spheroid, obovate, oblate, rhomboidal, elongate and clavate while the shape for Solanum pimpinellifolium was consistently round. The colours observed for Solanum lycopersicum were red, red with yellow patches, and yellowish-red while colour in S. pimpinellifolium was consistently red. Number of ribs on the fruits of the cultivated species ranged from 0–12 while rib was absent in the wild species. Noteworthy, were the fruit forms with beak-like protrusions at the apices of the cultivated species. The length-to-diameter ratio of fruits of the cultivated species was a reliable parameter for differentiating the elongated fruit forms from the other forms in the cultivated species

    Investigating the challenges of refinery construction in Nigeria: A snapshot across two-timeframes over the past 55 years

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    The sub-optimal performance of state-owned refineries in Nigeria has led to a significant gap in the supply of refined petroleum products (RPPs) in the country. More so, the growing demand for these products has further widened the gap to the range of 500,000 – 600,000 barrels per day (bpd). Consequently, most of the imports for RPPs in Nigeria are being filled from the United States and North-Western Europe at the expense of the Nigerian economy. However, given the abundance of petroleum resources in Nigeria and its long history in the production of oil, it is unfortunate that the local refineries are hardly maintained to meet the needs of the local population. In addition, the inability of the Nigerian state to build additional refining capacity to cushion its domestic supply gap for RPPs has become a major concern. With more than 40 licenses issued to private companies since 2002, only two companies (Niger Delta Petroleum Resources Refinery and Dangote Oil Refinery) have made noticeable progress in new refinery construction. This paper is focused on investigating the current challenges of refinery construction in Nigeria. This is done with a view of comparing the drivers and enablers of productivity in construction in this sector during the period of 1965 – 1989 and how they differ from the current period of 2000 - 2019 in Nigeria. A systematic literature review within the academic journals, source documents from the industry, relevant interviews from published news media and consulting organisations were used to identify and categorise these challenges. The findings of this study were validated by interviews from experts across key industries in this sector. The study reveals that change of ownership structures from the government sector to the private sector between the two eras, present additional challenges. These challenges cut across availability of capital, inconsistent government priorities and access to land for construction. Others include cronyism and corruption, weak political will, unstructured refinery licensing scheme, security challenges and economic factors regarding the regulated downstream market in Nigeria. Key recommendations proffered to help solve these problems include a private sector-led partnership with the government in the form of public private partnerships (PPPs), a review of existing methods for licensing refineries for private organisations, the development of local manpower with relevant technical skills to help lower the cost of expatriate labour and the establishment of more designated clusters as free trade zones within the oil-producing Niger Delta. These recommendations will help lower the entry barriers for private organisations in this sector

    An analysis of the mediational effect of socio-cultural factors on student’s career choice outcomes in the built environment: applying the socio-cognitive career theory

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    Investigations into career development revealed the significant influence of social and cultural determinants, notably familial factors, on children’s professional aspirations. Such aspirations are moulded by their milieu, individual interests, academic environments, and socio-economic contexts. South Africa’s unique socio-political history introduces complexity into career development pathways. The intricate relationships between ethnicity, gender, and socio-economic backgrounds vis-a-vis career outcomes of South African youth remain underexplored. This research aimed to understand these influences within the construction domain, emphasising cognitive facets such as self-efficacy and societal endorsements. The Social Cognitive Career Theory (SCCT) served as the foundational framework, with structural equation modelling employed for causal analysis. A focus was given to early university students, predominantly from Construction Management. The study showcased pathways for informed career decisions in construction and underscored the relevance of the SCCT, especially for women in traditionally male-dominated sectors. The study culminated in unveiling pathways for informed career decisions in construction, reinforcing the pertinence of the SCCT framework, especially concerning women in traditionally male-dominated spheres like construction. Acknowledging the scarcity of empirical studies using SCCT within the construction sphere is pertinent


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    Interpretation of seismic results from a complex geological formation can be very difficult both on-field and off-field. The spectra ratio (SR) time-dependent method was derived using established geological principles. The spectral amplitude was analyzed numerically to affirm the reliability of the method on field operations. It was observed that the SR time-dependent method could initiate a natural correction to the attenuated seismic amplitude at each given interval during a seismic operation. The multi-layer implementation of the adopted method showed great success with the most accurate result at n = 0.1 for the fourth term on a newly-propounded volumetric table. Most volumetric results from the Niger- Delta showed correspondence with the volumetric analysis of the fourth term. One of the on-field volumetric results was obtained in the third term. The derivation of the volumetric table is to further enhance more accurate exploration using the reflective seismic technique
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