# The development of an optimal earthmoving machine replacement interval model in an open-cast mining environment

Burger, Dirk Adriaan (2001-12)

Thesis (MBA)--Stellenbosch University, 2001.

Thesis

ENGLISH ABSTRACT: The replacement of earthmoving machines forms a significant portion of the annual capital expenditure on South African mines. The decision on the timing of the replacement varies substantially between different operations, but frequently it is not based on any scientific study or analysis. The reason for this is that most textbooks propose complex calculations for the determination of an optimal replacement point, and subsequently the mathematical effort serves as a deterrent to those who are tasked with replacement evaluation. This study proposed a simple graphic method which is suitable for everyday use, and which can quickly be adapted when conditions change. The model furthermore makes provision for the analysis of the replacement of both the current machines (the so-called defenders) as well as an evaluation of potential replacement machines (the so-called challengers). In addition, the model also makes provision for the incorporation of non-cash factors, such as productivity and reliability.

AFRIKAANSE OPSOMMING: Die jaarlikse vervanging van grondversuiwing masjienerie maak 'n groot deel uit van die kapitaalplan van die meeste Suid-Afrikaanse myne. Die metode van besluitneming oor die presiese tydsberekening van die vervanging verskil ook tussen die verskillende organisasies, maar dit is selde gebaseer op 'n wetenskaplike analiese. Die rede hiervoor is dat die meeste handboeke komplekse wiskunde modelle voorstel vir die berekening van 'n optimate masjien vervangingspunt. The kompleksiteit gee daartoe aan dat baie nie kans sien om dit te probeer doen nie, en gevolging wegskram van enige analise. Hierdie studie projek stel 'n eenvoudige grafiese model voor vir allerdaagse gebruik, wat ook vinning gewysig kan word as toestande verander. The model maak ook voorsiening vir die analise van beide die huidige masjien (die sogenaamde verdediger) se optimale vervangingspunt, sowel as die evaluasie van potentiele nuwe masjiene (die sogenaamde aanvallers.) Die model maak verder ook voorsiening vir faktore wat nie normaalweg in geldwaarde beskryf word nie soos byvoorbeeld produktiwiteit en betroubaarheid.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/52511

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