P.S. Kruger

An Evaluation Model for Quantifying System Value

Abstract The value of a system to the user is a paramount consideration in making decisions about the system. Quantification of system value perspectives, even if precision is restricted to orders of magnitude, can be useful in communication processes during decision making through unambiguous structuring of the relevant issues so that rational risk trade-offs and sensitivity analyses can be performed. This paper presents a model for quantifying system value.

THE NECESSITY OF INFORMATION QUALITY FOR EFFECTIVE BUSINESS INTELLIGENCE

Data quality, or rather the lack thereof, has been the downfall of many Data warehousing (DW) / Business Intelligence (BI) projects. The concept of Information Quality (IQ) has become increasingly important as the popularity of Business Intelligence (BI) increases. Industrial engineers have played a key role in the development and implementation of Total Quality Management (TQM) principles that are widely used in the manufacturing environment. In the information era, industrial engineers can apply the same principles to data. This article aims to identify strategies and processes to improve IQ that will eventually lead to data warehouses with complete, accurate and timely data that consistently meets the requirements of knowledge workers in their quest to make improved business decisions. OPSOMMING Die gebrek aan datakwaliteit het al menige Databergings- en Besigheidsintelligensieprojekte laat sneuwel. Die konsep van Inligtingskwaliteit word al meer prominent soos die gewildheid van Besigheidsintelligensie toeneem. Bedryfsingenieurs het reeds ‘n sleutelrol gespeel in die ontwikkeling en implementering van Totale Kwaliteitsbestuurbeginsels wat algemeen in die vervaardigingsomgewing gebruik word. In die inligtingsera kan bedryfsingenieurs dieselfde beginsels ook op data toepas. Hierdie artikel identifiseer strategiee en prosesse om inligtingskwaliteit te verbeter wat uiteindelik behoort te lei tot datastore met volledige en akkurate data wat betyds en konsekwent aan kenniswerkers se behoeftes voldoen en hulle instaat stel om beter besigheidsbesluite te neem.

The design of a microcomputer based simulator for production management training

Abstract The proliferation of independent computer based systems in some manufacturing companies has more than often led to islands of automation. The effective integration of such systems has become imperative for the complete realization of the advantages of computer based systems in the manufacturing environment. The teaching of the fundamental principles of production management and control to engineering students is suffering from the same lack of integration and a need for more effective training methods has been identified. The purpose of this paper is to demonstrate that the computerized training simulator, CIMSIM, might fulfill this need.

THE ART OF SIMULATION MODELLING

It is the contention of the author that practising the “art” of modelling has been, and always will be, of great importance to the ultimate success of any project employing a simulation approach. Yet very few publications address this aspect of simulation modelling exclusively. This paper is an attempt to focus attention on some of these “softer” issues of simulation modelling. By using the concept of a Simulation Syndrome the paper endeavours to highlight some of these issues and to serve as a reminder to simulation modellers of some aspects of the “art” of modelling that are often taken for granted. “Advice is seldom welcome; and those who want it the most always like it the least” Lord Chesterfield OPSOMMING Die outeur is van mening dat die “kuns” van modellering van groot belang is vir die uiteindelike sukses van enige projek waar gebruik gemaak word van ’n simulasiebenadering. Nietemin bestaan daar weinig publikasies waar hierdie aspek van simulasiemodellering spesifiek aangespreek word. Hierdie artikel is ’n poging om die aandag te vestig op sommige van die “sagter” aspekte van simulasiemodellering en die doelwit word bereik deur gebruik te maak van die konsep van ’n Simulasie-Sindroom. Op hierdie wyse word die gebruikers van simulasiemodellering herinner aan somminge aspekte van die “kuns” van modellering wat dikwels as vanselfsprekend aanvaar word. “Advice is seldom welcome; and those who want it the most always like it the least”

INDUSTRIAL ENGINEERING : ROOTING FOR ROOTS, HANKERING FOR HEROES

The “roots” of Industrial Engineering are certainly extensive, diverse and deep. Similarly, there are numerous historical “heroes” that made significant contributions to the development of the Industrial Engineering discipline. For the sake of argument, this article will assume that Industrial Engineering has at least two identifiable main roots, namely Determinism and Stochastism. The article attempts to trace the early history 1 of the stochastic root which is very closely linked to the history of probability and statistics and hence games of chance, gambling and divinity. Therefore, the life and times, contributions and personalities of some of the heroes and villains, champions and sad cases of the stochastic world, will be briefly discussed in a somewhat light-hearted, but not necessarily flippant, manner. OPSOMMING Die “wortel en tak” van Bedryfsingenieurswese is sekerlik van groot omvang, van diverse aard en diep gesetel. Verskeie historiese “helde” het betekenisvolle bydraes gemaak tot die ontwikkeling van die Bedryfsingenieurswesevakgebied. Ter wille van betoogvoering sal in hierdie artikel aanvaar word dat Bedryfsingenieurswese uit minstens twee identifiseerbare sub-vakgebiede bestaan naamlik : Die Determinisme en die Stogasme. ’n Poging word aangewend om die vroee geskiedenis van die stogasme na te speur wat op sy beurt aaneengesnoer is met die geskiedenis van die waarskynlikheidsleer en statistiek en dus toevalspelle, dobbelary en wiggelary. Die lewenswyse, tydsgewrig, bydraes en persoonlikheidseienskappe van ’n aantal helde en skurke, kampioene en prulle van die stogastiese wereld word kortliks bespreek, op ’n ietwat lighartige maar nie noodwendig ligsinnige wyse. 1 History is by no means an exact science and is certainly subject to random and/or systematic errors, uncertainty, personal interpretation and opinion. Some of the “facts” contained in this paper may be apocryphal in nature and the truthfulness and accuracy of the information may at best be declared as “beyond a reasonable doubt”.

Generic building blocks for simulation modelling of stochastic continuous systems

The key objective is to present the generic building blocks of a methodology that can be used to model stochastic continuous systems efficiently. The original simulation model of a realworld system is used as the basis for the development of a generic modelling methodology. The generic building blocks of the methodology are used to construct two new simulation models using two different simulation software packages (Arena and Simul8). The evaluation method, the determination of adequate sample sizes and the verification and validation of the models are discussed. The models and software packages are compared and conclusions are presented. OPSOMMING Die hoofdoelwit is om die generiese boublokke van ‘n metodiek voor te hou wat gebruik kan word om stogastiese kontinue stelsels doeltreffend te modelleer. Die oorspronklike simulasiemodel van ‘n werklike-wereld-stelsel word gebruik as die basis vir die ontwikkeling van ‘n generiese modelleringsmetodiek. Die generiese boublokke van die metodiek word gebruik om twee nuwe simulasiemodelle te konstrueer met twee verskillende simulasiesagtewarepakkette (Arena en Simul8). Die evaluasiemetode, die vasstelling van voldoende monstergroottes en die verifikasie en validering van die modelle word bespreek. Die modelle en sagtewarepakkette word vergelyk en gevolgtrekkings word voorgehou.

Software tools for the development of Expert Systems

ENGLISH ABSTRACT: This paper will attempt to provide information with regard to some of the expert system development tools that are available. It will also provide some guidelines which may be used in the selection of appropriate system development software. AFRIKAANSE OPSOMMING: Hierdie artikel sa poog om informasie te verskaf oor sommige van die ekspertstelselontwikkelingsprogrammatuur wat tans beskikbaar is. Riglyne word verskaf wat gebruik mag word in die keuse van toepaslike ontwikkelingsprogrammatuur.

THE VALUE OF MONEY AND THE FLAW-OF-AVERAGES

Given the state of uncertainty in the world, decision analysis and decision-making under conditions of uncertainty are becoming more important. However, any rational decision-making requires a criterion on which to base the decision — which implies the availability of a value system. This paper will provide a short introduction to the basic principles of some value systems and related concepts such as the value of money, the flaw-of-averages, interest and discount rates, utility theory, and decision analysis. It will employ a Monte Carlo simulation approach to investigate the possible influence of the flaw-of-averages on interest calculations, net present value calculations, and decision trees. It will show that, under certain circumstances, the flaw-of-averages might be present and significant.

THE POWER OF ONE: BENFORD’S LAW

The concept of Benford’s law, also known as the first-digit phenomenon, has been known to mathematicians since 1881. It is counter-intuitive, difficult to explain in simple terms, and has suffered from being described variously as ‘a numerical aberration’, ‘an oddity’, ‘a mystery’ – but also as ‘a mathematical gem’. However, it has developed into a recognised statistical technique with several practical applications, of which the most notable is as a fraud detection mechanism in forensic accounting. This paper will briefly discuss and demonstrate the special numerical characteristics of Benford’s law. It will attempt to investigate the law’s possible application to the detection of data manipulation and data tampering that might exist in papers published in engineering and scientific journals. Firstly, it will be applied to an investigation of the so-called Fisher-Mendel controversy. Secondly, Benford’s analysis will be applied to six recently published papers selected from the South African Journal of Industrial Engineering .

PROBABILITY MANAGEMENT AND THE FLAW-OF-AVERAGES

Uncertainty is ever-present and is an integral part of life. Recognising the existence of uncertainty and its possible effects on decision-making may be important for the profitability, financial success, or even survival of an organisation. A relatively new discipline, - known as probability management, - has recently emerged as part of operations research/management science. This paper will attempt to provide a brief introduction to the concepts of probability management and the motivation behind its development. One of the major driving forces resulting in this development is the phenomenon known as the ‘ flaw-of-averages ’ . The flaw-of-averages has important consequences in industrial engineering, financial, business, and economic models. The classic newsvendor problem will be used as an illustrative example. However, the main purpose of this paper is to discuss the most important characteristics of the flaw-of-averages. It will investigate and attempt to quantify some of the generic factors that may have an influence on the existence and severity of the flaw-of-averages and its expected consequences. Various models will be developed, and experiments will be conducted using Microsoft Excel as a modelling tool and an experimental approach based on Monte Carlo simulation modelling.