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Acta Structilia : Journal for the Physical and Development Sciences - latest Issue
Volume 24 Number 2, December 2017
Authors: Chipozya Kosta Tembo-Silungwe and Nthatisi Khatleli
Source: Acta Structilia : Journal for the Physical and Development Sciences 24, pp 1 –43 (December 2017) http://dx.doi.org/10.18820/24150487/as24i2.1
Authors: Kobus van der Walt and Douw Boshoff
Source: Acta Structilia : Journal for the Physical and Development Sciences 24, pp 44 –76 (December 2017) http://dx.doi.org/10.18820/24150487/as24i2.2
There are numerous factors that influence the price of a farm and some of these factors are not monetary related. This makes the task of the valuer complex and increases the possibility of large differences in the estimated market value determined and the actual selling price. This article reports the results of a study that analysed the unique and distinctive attributes of farms, in order to determine whether it is possible to develop a linear multiple regression model for the valuation of farms (which satisfies accuracy requirements) with reasonably available data. The improvement of accuracy levels of Multiple Regression Analysis (MRA) models as well as the limitations of using these MRA models during farm evaluations was also studied. By following a stepwise regression approach, 60 farms, primarily located in the eco-zone “mixed bushveld” western area of the Limpopo province, were analysed using ten independent variables. Three models have been developed. The results showed that a fairly accurate regression model could be developed. However, a model that achieves a high level of accuracy could not be developed, due to multifaceted reasons, including non-farm factors and the size of the geographical areas. Accurate MRA valuation estimates will be to the advantage of individual farm owners regarding their municipal tax assessments. It will lead to a wider use of MRAs for the valuation of farms, but great circumspect should be taken when using MRA models in farm valuations. This is due to the possibility that the MRA models do not satisfy minimum accuracy requirements. It is difficult, but possible, to develop a fairly accurate MRA model for the valuation of farms. Therefore, if currently used MRA models are not fairly accurate for municipal valuation purposes, it should be possible to improve the accuracy. Further research is recommended in the use of other regression techniques such as non-linear, geographic weighted regression and quantile regression. These other techniques would, however, require a larger data sample, in order to provide meaningful results.
Daar is veelvuldige faktore wat die prys van ’n plaas beïnvloed, wat nie noodwendig suiwer finansieël van aard is nie. Dit maak die taak van die waardeerder moeilik en kompleks, wat weer veroorsaak dat die moontlikheid bestaan dat daar groot verskille tussen die gewaardeerde waardes en die verkooppryse van plase voorkom. Hierdie artikel rapporteer die resultate van ’n studie wat die unieke en onderskeidende eienskappe van plase ontleed ten einde te bepaal of dit moontlik is om ’n liniêre regressie-analiese model te ontwikkel (wat aan minimum akkuraatheidsvlakke voldoen) met redelik beskikbare inligting, vir die waardasie van plase. Die verbetering van die akkuraatheidsvlakke van MRAmodelle sowel as die beperkings van hierdie MRA-modelle, vir gebruik in plaas waardasies, is ook nagevors. Deur middel van ’n stapsgewyse regressie-analiese metode, is 60 plase wat hoofsaaklik in die “gemengde bosveld” ekosone, in die westelike gedeelte van die Limpopo-provinsie geleë is, ontleed deur van 10 onafhanklike veranderlikes gebruik te maak. Drie modelle is ontwikkel. Die resultate het aangetoon dat ’n regressiemodel ontwikkel kan word wat redelik akkuraat is, maar ’n model met ’n hoë mate van akkuraatheid kon nie ontwikkel word nie as gevolg van veelvuldige redes, insluitend redes wat nie direk verwant is aan plaasfaktore nie en die grootte van die geografiese gebiede. Alhoewel akkurate MRA-waardasies tot voordeel sal wees van plaas eienaars vir die bepaling van munisipale belastingwaardes en dit sal lei tot ’n wyer en meer algemene gebruik van MRA’s vir plaaswaardasies, moet groot versigtigheid aan die dag gelê word met die gebruik van MRA-modelle in plaaswaardasies omdat dit waarskynlik is dat die MRA-modelle nie aan minimum akkuraatheidvereistes voldoen nie. Dit is moeilik, tog moontlik, om ’n MRA-model vir plaaswaardasies te ontwikkel wat redelik akkuraat is. Dus, waar MRA-modelle vir munisipale waardasies gebruik word, wat nie redelik akkuraat is nie, behoort die akkuraatheid verhoog te kan word. ’n MRA-modelwaardasie sal egter nooit die waardasie van ’n ervare en kundige professionele waardeerder kan vervang, wanneer ’n maksimale akkurate waardasie benodig word nie.
Authors: Ibrahim Saidu and Winston Shakantu
Source: Acta Structilia : Journal for the Physical and Development Sciences 24, pp 77 –105 (December 2017) http://dx.doi.org/10.18820/24150487/as24i2.3
Material waste and cost overrun have been identified as common problems in the construction industry. These problems occur at both pre- and post-contract stages of a construction project. As a result of a dearth of empirical research and low level of awareness, the majority of managers of construction projects in Nigeria pay hardly any attention to material waste issues that affect cost overrun. This article examines the material waste issues that affect cost overruns at the post-contract stage of building projects. The study covers building construction projects in Abuja, Nigeria. In-depth interviews were conducted with professionals using purposive sampling technique. It is purposive, because only building professionals handling projects that are worth over eight million USD are consulted/interviewed. The professionals included 15 project managers, nine quantity surveyors, five site engineers and one senior technical officer of a waste management department/unit. The interviews were on issues relating to material waste and cost overruns at the post-contract stage of a project. The collected data were analysed manually, using the deductive approach. This involves constant comparative analysis of the data to generate common patterns on material waste and cost overrun. The research found that poor quality-of-procurement management, construction management, and site management would cause material waste, which contributes to project cost overruns. A good-quality procurement management entails procuring the appropriate materials, at the right time and in accordance with specifications. Rework, site accidents, inadequate site security/fencing, poor site organisation and discipline,construction-site disputes, lack of experience, and lack of co-ordination among the parties all contribute to material waste and cost overruns. It can be concluded that proper attention to material waste issues has the potential to minimise the rate of cost overrun at the post-contract stage of a project. It is recommended that careful attention should be paid to the issues identified in this study, as they would help reduce the rate of material waste and cost overrun for projects.
Materiaalafval en koste-oorskryding word geïdentifiseer as algemene probleme in die konstruksiebedryf. Hierdie probleme vind plaas in beide vooren na-kontrakstadiums van ’n konstruksieprojek. As gevolg van ’n gebrek aan empiriese navorsing en lae vlak van bewustheid, gee die meeste bestuurders van konstruksieprojekte in Nigerië min aandag aan materiaalafvalkwessies wat kosteoorskryding beïnvloed. Hierdie artikel ondersoek die materiaalafvalkwessies wat koste-oorskryding in die na-kontrakstadium van bouprojekte beïnvloed. Die studie dek boukonstruksieprojekte in Abuja, Nigerië. In-diepte onderhoude met professionele persone is gehou met behulp van doelgerigte steekproefnemingstegnieke. Dit is doelgerig omdat slegs professionele persone wat projekte hanteer wat meer as agt miljoen dollar werd is, geraadpleeg/ ondervra is. Die professionele persone het 15 projekbestuurders, nege bourekenaars, vyf terreiningenieurs en een senior tegniese beampte van ’n afvalbestuursafdeling/-eenheid ingesluit. Die onderhoude het gegaan oor die kwessies wat verband hou met wesenlike afval en koste-oorskryding by die na-kontrakstadium van ’n projek. Die versamelde data is geanaliseer deur die deduktiewe benadering te gebruik. Dit behels konstante vergelykende analise van die data om algemene patrone op materiaalafval en koste-oorskryding te genereer. Die navorsing het bevind dat swak gehalte-van-verkrygingsbestuur, konstruksiebestuur en terreinbestuur materiaalafval tot gevolg sal hê, wat bydra tot die koste van die projekkoste. Goeie gehalte-verkrygingsbestuur behels die verkryging van toepaslike materiale, op die regte tyd en in ooreenstemming met spesifikasies. Herstelwerk, terreinongelukke, onvoldoende terreinbeveiliging/- heining, swak terreinorganisasie en dissipline, geskilpunte op die bouplek, gebrek aan ondervinding en gebrek aan koördinasie tussen partye dra alles by tot materiaalafval en koste-oorskryding. Daar kan tot die gevolgtrekking gekom word dat behoorlike aandag aan materiaalafvalkwessies die potensiaal het om die koers van koste-oorskryding in die na-kontrakstadium van ’n projek te verminder. Daar word aanbeveel dat deeglik aandag gegee word aan die probleme wat in hierdie studie geïdentifiseer word, aangesien hulle sal help om die hoeveelheid afval en die koste-oorskryding vir projekte te verminder.
Stakeholders’ perception of critical success factors for sustainable facilities management practice in universities in sub Saharan Africa
Authors: Bankole Awuzie and Rasheed Isa
Source: Acta Structilia : Journal for the Physical and Development Sciences 24, pp 106 –127 (December 2017) http://dx.doi.org/10.18820/24150487/as24i2.4
Authors: Davison Murwira and Michiel Bekker
Source: Acta Structilia : Journal for the Physical and Development Sciences 24, pp 128 –145 (December 2017) http://dx.doi.org/10.18820/24150487/as24i2.5
Building and infrastructure projects at the North- West Province Department of Public Works and Roads (NW DPWR) often perform poorly in terms of overrunning both the original approved timeline and the budget. Adding to poor time and cost performances, these projects often do not meet the desired functional requirements. This article reports on findings of a study which investigated the causes of these poor performances in the NW DPWR. Fifty potential causes of poor performance were identified from literature. These factors were grouped under three main related categories of owner-related, contractorrelated and consultant-related and were subjected to a questionnaire survey to identify the most critical causes of failure. The results were analysed using the Relative Importance Index (RII) and Spearman’s Rank Correlation Coefficients. The results indicated that the most significant causes of poor building and infrastructure project performance in the NW DPWR include underestimation of project cost, the lack of experience in executing projects, contractor’s cash-flow constraints, corruption and bribery during the bidding and contract award phase, as well as poor site management and supervision. Recommendations are made to prevent similar causes of projects failure in the NW DPWR in future.
Bou- en infrastruktuurprojekte by die Noordwes Provinsie se Departement van Openbare Werke en Paaie (NW DPWR) ondervind gereeld tydvertragings in projekvoltooiing sowel as probleme soos oorspandering en die gebrek aan voldoening aan funksionele spesifikasies. Hierdie artikel rapporteer resultate van ’n studie wat onderneem is ten einde die redes waarom projekte in die NW DPWR swak presteer, te ondersoek. Vanuit literatuur is vyftig potensiële redes vir projekfaling geïdentifiseer. Die redes is in drie verwante kategorieë gegroepeer, naamlik eienaarverwante, kontrakteurverwante en konsultantverwante kategorieë. Deur middel van ’n vraelysopname is die mees kritieke redes vir projekfaling geïdentifiseer. Die resulate is ontleed deur gebruik te maak van ’n Relatiewe Sterkte Indeks asook die Spearman Rangorde Korrelasie Koëffisiënte. Die resultate toon dat die mees beduidende redes vir projekfaling in NW DPWR sluit onderberaming van projekkoste, gebrekkige ervaring in projekimplementering, beperkte kontantvloei deur kontrakteurs, korrupsie en omkopery tydens die tenderproses en kontrakaanstellings, sowel as swak terreinbestuur en toesig in. Aanbevelings is gemaak om soortgelyke probleme met toekomstige projekte in die NW DPWR te beperk.
Authors: Tariene Wilcocks and Jacques Laubscher
Source: Acta Structilia : Journal for the Physical and Development Sciences 24, pp 146 –167 (December 2017) http://dx.doi.org/10.18820/24150487/as24i2.6