39 research outputs found
A generic business model and management information system for quick ERP implementation in a project-driven SME
Thesis (MScEng)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: A demand exists in SMEs to implement an ERP system to provide intime
transaction and management information to the employees and
management respectively. The reason for this study developed from
problems experienced in the past with ERP implementations.
As a first step, a generic business model for project management in
an SME was developed. This business model is based mainly on the
PMBOK. Experienced project management consultants provided
inputs for the business model. CAE accepted the business model
after a few reviews. The business model was implemented in CAE
and the employees trained to perform their daily tasks on Omuzik by
using the processes suggested by the business model.
The five main processes in the project management business model
are Initiating, Planning, Executing, Controlling and Closing. The
model is complete with inputs to the processes and the resulting
outputs from them. The business model was implemented on
Omuzik, and comments were included with every business process.
Reports for project management were developed to provide in the
information requirements of the project managers. The reports
developed and deployed aim at providing detail and summary
information to assist project managers in performing project control.
The reports were developed and implemented and are currently used
by the CAE project managers.
The project management business model and reports fit into the
bigger project for the complete enterprise with great success. The
bigger project has completed the templates and is ready for the first
fast implementation where the methodology will be tested.AFRIKAANSE OPSOMMING: 'n Behoefte bestaan by kleinsakeondernemings om ERP-stelsels te
implementeer om in hulle intydse inligtingsbehoeftes vir transaksieinligting
aan werknemers en bestuursinligting aan bestuur te voorsien.
Die rede vir hierdie studie het ontwikkel uit die probleme wat in die
verlede met ERP-implementerings ondervind is.
As 'n eerste stap is 'n generiese besigheidsmodel vir projekbestuur in
'n kleinsakeonderneming ontwikkel. Die besigheidsmodel is
hoofsaaklik op die PMBOK gebaseer. Ervare projekbestuur
konsultante het insette gelewer vir die besigheidsmodel. CAE het die
besigheidsmodel ná 'n paar hersienings aanvaar. Die
besigheidsmodel is geïmplementeer, en die werknemers is opgelei
om in hulle daaglikse werk Omuzik vir die voorgestelde
besigheidsmodelprosesse te gebruik.
Die vyf hoofprosesse in die projekbestuur-besigheidsmodel is
Inisiasie, Beplanning, Uitvoer, Beheer en Afsluiting. Die model is
afgehandel met insette vir die prosesse en die resulterende uitsette
daarvan. Die besigheidsmodel is op Omuzik geïmplementeer, en
kommentaar is by elke proses ingesluit.
Verslae vir projekbestuur is ontwikkel om in die inligtingsbehoeftes
van die projekbestuurder te voorsien. Daar word beoog om met die
verslae omvattende en samevattende inligting te voorsien aan
projekbestuurders om projekbeheer te kan uitoefen. Die verslae is
ontwikkel en geïmplementeer en word deur CAE-projekbestuurders
gebruik.
Die projekbestuur-besigheidsmodel en verslae pas met sukses in by
die groter projek vir die totale onderneming. Die groter projek is in die
proses om die model te verpak vir die eerste loodsprojek
Forecasting South African containers for international trade : a commodity-based approach
The original publication is available at http://www.jtscm.co.za/index.php/jtscm/article/view/72The most common approach used internationally for forecasting international trade
containers is models based on the correlation between container trade and economic
growth. While the strong historical correlation is indisputable, this paper argues that
there will be saturation in the propensity to containerise as all the suitable volumes of
the underlying commodities shift to containers over time. In addition, the link between
freight transport and GDP will decouple as more sustainable approaches to economic
development, and therefore freight transport, are necessitated by economic and
environmental realities. A commodity-based model, taking into account the underlying
drivers of containerisation, is proposed here as a more realistic forecast of container
demand. This could have a material impact on how large-scale investment decisions are
directed.Publishers' Versio
A network maturity mapping tool for demand-driven supply chain management : a case for the public healthcare sector
CITATION: Bvuchete, M., Grobbelaar, S. S. & Van Eeden, J. 2021. A network maturity mapping tool for demand-driven supply chain management : a case for the public healthcare sector. Sustainability, 13(21):11988, doi:10.3390/su132111988.The original publication is available at https://www.mdpi.comPublication of this article was funded by the Stellenbosch University Open Access FundThe healthcare supply chain is a complex adaptive ecosystem that facilitates the delivery of health products to the end patient in a cost-effective way. However, low forecast accuracy and high demand volatility in healthcare supply chains have resulted in an increase in stockouts, operational inefficiencies, poor health outcomes, and a significant increase in supply chain costs. To cope with these challenges, organisations are trying to adopt demand-driven supply chain management (DDSCM) operating practices which have been established in other sectors such as the telecommunications, fruit, and flower industries. However, previous studies have not considered these practices in the healthcare industry, and hence no methodologies exist that support the implementation of these practices in this context. Moreover, current studies present cases where the focus has been on improving and expanding individual organisational performance, but no supply chain network-level studies exist on the healthcare industry. Therefore, this paper provides a network-level analysis when addressing DDSCM in the healthcare industry. A grounded theory-based approach coupled with a conceptual framework analysis process was used to leverage a systematized literature review methodology with the development of a network maturity mapping tool for DDSCM which was validated in the public healthcare sector.https://www.mdpi.com/2071-1050/13/21/11988Publisher's versio
Identification of key target markets for intermodal freight transport solutions in South Africa
The original publication version is available at http://www.journals.co.za/ej/ejour_jtscm.htmlThe Accelerated and Shared Growth Initiative for South Africa (AsgiSA) identified South
Africa’s freight logistics challenges as among the key binding constraints on the country’s
growth aspirations. The research presented here points to the structural imbalance
between road and rail freight transport as one of the key contributors to this state of
affairs. Most long-distance corridor transport has been captured by road. However, longdistance
transport is a market segment that is very suitable for intermodal transportation:
rail is utilised for the high-density, long-distance component and road for the feeder and
distribution services at the corridor end points. A market segmentation approach is
developed to identify the corridors and industries that are natural candidates for such
solutions, thereby paving the way for role-players and stakeholders to initiate a dialogue
on the development of appropriate solutionsPublishers' Versio
A model for the translation of South African economic activity into shipping container demand
Thesis (PhD)--Stellenbosch University, 2018.ENGLISH ABSTRACT: Quay wall container forecasts are often done by broad-stroke methods with large-scale infrastructure decisions then based on these forecasts. This research problem requires an investigation into more accurate long-term forecasting methods. A mixed methods research design was followed, combining quantitative and qualitative data, with the primary objective to establish design requirements for and to develop a content-based quay wall container framework. Secondary objectives were to also establish design requirements for quay wall modelling frameworks for transhipment and empty containers. These secondary objectives originated from exposure to literature and data from the primary research.
The aim of this dissertation was to redefine the importance and usefulness of content-based container forecasting techniques. This would enable port planners to base their container volume forecasts on economic activity, i.e. validated demand, and not on the perceived reality of historic containers or other broad indicators.
The mixed method design combined literature on container modelling techniques, demand-side and supply-side container shipping factors and the impact of port networks on quay wall container volumes. The literature showed only a few scholars venturing into the field of high granularity container forecasting methods. Those that did propose methods used mostly derivatives of traded commodities like GDP, trade, or population growth as input drivers. Many scholars referred to, but very few used container contents in their modelling, mostly due to data unavailability.
Rich secondary datasets received from various parties, i.e. TNPA, SARS, TFR and shipping lines, were all instrumental in understanding the relevant parameters. All datasets contributed in their own way to the development of the final set of parameters. To support this secondary data, primary research was conducted with freight owners, industry associations, LSP’s, shipping companies, port authorities and terminal operators via a survey and focus groups. Feedback from survey respondents and focus groups confirmed the user requirements identified earlier. It also confirmed the importance of the identified requirements and the inputs that were obtained from analysing container content data.
Design requirements were consolidated from all the mixed methods research inputs. Key parameters to forecast full container volumes across the quay wall are:
• Spatial disaggregation to define outputs per international geographic region and per port;
• Rate of containerisation of each commodity;
• Commodity port preference;
• Physical container types;
• Weight of commodity per physical container type.
The container modelling frameworks and modelling process for three functional typologies, were developed based on the design requirements. The inputs, parameters, modelling process, forecasting influencers and outputs for each of the defined functional typologies were discussed separately with a confidence level for each of the aspects. The confidence levels provides an indication of the current status of the parameter values and provides guidance towards future improvement areas.
The container modelling frameworks went through a verification and validation process. The proposed model is expected to provide a more accurate container forecast to port infrastructure planners. Using these drivers in forecasting models will inform port planners with validated demand towards calculated decisions on initiating port container infrastructure projects at the right moment in time.AFRIKAANSE OPSOMMING: Kaaimuur houer vooruitskattings word dikwels gedoen deur breëstrook metodes met grootskaalse infrastruktuurbesluite wat dan gebaseer is op hierdie voorspellings. Hierdie navorsingsprobleem vereis 'n ondersoek na meer akkurate langtermynvoorspellingsmetodes. 'n Navorsingsontwerp met gemengde metodes is gevolg, deur kwantitatiewe en kwalitatiewe data te kombineer, met die primêre doelwit om ontwerpvereistes vir en die ontwikkeling van 'n inhoudsgebaseerde kaaimuurhouerraamwerk te vestig. Sekondêre doelwitte was om ook ontwerpvereistes vir kaaimuurmodelleringsraamwerke vir oorladings- en leë houers te vestig. Hierdie sekondêre doelwitte het natuurlik ontstaan uit blootstelling aan literatuur en data uit die primêre navorsing.
Die doel van hierdie proefskrif was om die belangrikheid en bruikbaarheid van inhoudsgebaseerde voorspellingsmetodes vir inhoud te herdefinieer. Dit sal hawebeplanners in staat stel om hul houervolume voorspellings op ekonomiese aktiwiteit te baseer, dit wil sê gevalideerde vraag, en nie op die waargenome werklikheid van historiese houers of ander breë aanwysers nie.
Die gemengde metode ontwerp kombineer literatuur oor houermodelleringstegnieke, vraagkant- en aanbodkant-houer verskepingsfaktore en die impak van hawe netwerke op kaaimuurhouervolumes. Die literatuur het slegs 'n paar aktiewe navorsers getoon in die veld van hoë diepte houer voorspellingsmetodes. Diegene wat metodes voorgestel het, het hoofsaaklik afgeleides van verhandelde kommoditeite gebruik, soos BBP-, handels- of bevolkingsgroei as insetdrywers. Baie navorsers verwys na, maar baie min gebruikte houerinhoud in hul modellering, meestal weens die onbeskikbaarheid van data.
Ryk sekondêre datastelle wat van verskillende partye ontvang is, soos TNPA, SARS, TFR en skeepsrederye, was instrumenteel in die verstaan van die relevante parameters. Alle datastelle het op hul eie manier bygedra tot die ontwikkeling van die finale stel parameters. Om hierdie sekondêre data te ondersteun, is primêre navorsing gedoen met vrageienaars, bedryfsverenigings, Logistieke diensverskaffers, rederye, hawe owerhede en terminaal operateurs via 'n opname en fokusgroepe. Terugvoer van opname respondente en fokusgroepe het die gebruikersvereistes wat voor hierdie gebeure geïdentifiseer is, bevestig. Dit het ook die belangrikheid van die geïdentifiseerde vereistes en die insette wat verkry is om die inhoud van die houerinhoud te ontleed, bevestig.
Ontwerpvereistes is gekonsolideer uit al die navorsingsinsette vir gemengde metodes. Sleutelparameters om volhouervolumes oor die kaaimuur te voorspel, is:
• Ruimtelike disaggregasie om uitsette per internasionale geografiese streek en per hawe te definieer;
• Verhouding van houerverpakking van elke kommoditeit;
• Kommoditeits hawe voorkeur;
• Fisiese houertipes;
• Gewig van kommoditeit per fisiese houertipe.
Die raamwerkmodelleringsraamwerke en modelleringsproses vir drie funksionele tipes, is ontwikkel op grond van die ontwerpvereistes. Die insette, parameters, modelleringsproses, voorspellings-invloede en uitsette vir elk van die gedefinieerde funksionele tipes is afsonderlik bespreek met 'n vertroue vlak vir elk van die aspekte. Die vertroue vlakke gee 'n aanduiding van die huidige status van die parameterwaardes en bied leiding oor toekomstige verbeterings.
Die houermodelleringsraamwerk het 'n verifikasie- en valideringsproses gevolg. Die model sal na verwagting 'n meer akkurate houervoorspelling vir haweinfrastruktuurbeplanners voorsien. Die gebruik van hierdie drywers in voorspellingsmodelle sal hawebeplanners van gevalideerde vraag inlig om berekende besluite te neem oor die inisiëring van hawe houerinfrastruktuurprojekte op die regte oomblik in tyd
Essential amino acid requirements for growth in woolled sheep
Thesis (PhD(Agric) (Animal Sciences))--University of Stellenbosch, 2006.This project consisted of five studies. The objectives were to determine the essential
amino acid (AA) requirements of growing woolled lambs (Merino and Dohne Merino)
and the essential AA profile of duodenal digesta pre-dominantly derived from microbial
protein. The limiting essential AA`s in high rumen degradable protein (RDP) diets to
growing lambs, where microbial protein is the primary source of AA`s, were also
identified.
The first study determined the essential AA profile of duodenal protein on a high rumen
degradable diet and evaluated the impact of dietary RDP concentration and source [true
RDP vs. non-protein nitrogen (NPN)] on the AA composition of supplied in the
duodenum. The first trial in this study evaluated the effects of increasing true RDP levels
on the essential AA composition of duodenal protein primarily derived from rumen
microbes. The lambs had free access to wheat straw and fresh water. The daily RDP
supplements were administered in two equal doses into the rumens through rumen
cannulas at 07:00 and 19:00. Duodenal digesta was extracted with 6h intervals through
T-type cannulas, inserted proximally to the common bile duct. Sampling time was
advanced 2h every day to obtain duodenal samples on every even hour of a 24h period
after three days. As expected, deficient RDP limited the supply of essential AA`s in the iv
duodenum. When the true RDP supplements increased, the duodenal flow of essential
AA`s also increased concomitantly, but appeared to level off at the higher RDP levels.
Despite the positive quantitative effects of true RDP supplementation on AA supply to the
duodenum, the AA profile in the duodenum was unaltered. Consequently, the essential
AA profile of duodenal protein of sheep receiving high RDP diets, where microbial
protein is the primary source of AA`s in the duodenum, is relatively constant and
insensitive to dietary RDP concentration.
In the second trial the effects of RDP source (true RDP vs. NPN) on the essential AA
profile of duodenal protein on high RDP diets were evaluated by substituting increasing
amounts of urea for true RDP in isonitrogenous teatments. Higher NPN increments
reduced the daily supply of essential AA`s in the duodenum. In corroboration of the first
trial, the AA profile of the duodenal protein was very constant, irrespective of the RDP
source. Since microbial protein is the major source of duodenal AA`s on high RDP diets,
this study supports the view that microbial protein has a relatively constant AA profile,
but microbial protein yield varies according to several rate limiting factors in the rumen.
A constant microbial AA profile allows accurate estimates of microbial essential AA
supply in the small intestine if microbial protein production and fluid and particulate
outflow rates from the rumen can be accurately predicted. This allows the development
of more accurate undegradable protein (UDP) supplementation strategies, based on the
essential AA requirements of animals.
In the second study growing male Merino and Dohne Merino lambs were slaughtered at
different weights and body condition scores. The digesta was removed from the stomachs
and intestines and every organ or body part were weighed to determine the whole empty
body (WEB) composition. The WEB was partitioned into the carcass, internall offal
(stomachs, intestines, organs and blood) and external offal (head, feet, skin and wool).
No differences were apparent in the proportional weight distribution of similar body
components of the same breed at different ages. In a comparison between breeds, the
proportional weight contributions of the carcasses from both breeds to the WEB weight
were remarkably similar at both slaughtering stages. The Dohne Merino lambs had
proportionally larger internal offals and smaller external offals than the Merino lambs at
both slaughters. Unless the essential amino acid compositions of the internal and external
offals were identical to the carcass, the dissimilarities in weight and protein allocation to these two components within the WEB`s of Merino and Dohne Merino lambs imply a
distinct WEB essential AA composition for each breed.
The apparent digestibilities of dry matter (DM), crude protein (CP), energy, acid
detergent fibre (ADF), neutral detergent fibre (NDF), fat and ash did not differ between
Merino and Dohne Merino lambs. Energy retention was also similar for the two breeds,
but the Merino lambs retained considerably more N than the Dohne Merino lambs. This
may also impact on the respective amino acid requirements of the lambs. Since the
Merino lambs utilise N more efficiently, they may have potentially lower essential amino
acid requirements to achieve a similar growth rate.
The WEB essential AA compositions of growing Merino and Dohne Merino lambs were
determined in the third study. Based on the ideal protein concept, the WEB essential AA
profile was accepted as representative of the AA requirements for growth. The use of a
single body part as a representation of the WEB AA profile was also evaluated.
Differences in the proportional weight and protein contribution of the three body
components (carcass, internal offal and external offal) of the two breeds strongly
suggested that the WEB AA composition of the breeds would differ, because of likely
differences in the AA profiles of these components. The essential AA profiles of the
carcasses from the two breeds were surprisingly similar. However, the essential AA
compositions of the internal offal and external offal differed substantially from each
other, as well as from the carcass. In addition, the internal offal and external offals of
each breed had characteristic essential AA profiles. Inevitably, the WEB essential AA
profiles of Merino and Dohne Merino lambs differed considerably. Only the leucine and
phenylalanine concentrations in the WEB`s of Merino and Dohne Merino lambs did not
differ. Significant differences in the concentrations of eight essential AA`s implied that
the two breeds have different AA requirements for growth. The different AA
compositions of the internal and external offal within each breed also illustrated that the
use of a single body component, like the carcass, as a predictor of WEB essential AA
composition contains considerable inaccuracies.
The essential AA index indicated that the duodenal protein, primarily derived from rumen
microbes, provided approximately 81 % of the qualitative AA requirements of growing
lambs. During periods of sufficient availability of very low-quality forage, as the diet in this study simulated, microbial protein is not able to support maximum growth. The first
two limiting AA`s (histidine and methionine) could not even support daily growth rates of
100 g/d. This is very low and stresses the need for effective undegradable AA
supplementation under these conditions.
Chemical scores identified histidine as the first limiting AA in high RDP diets
(predominantly microbial protein), followed by methionine, leucine, arginine and
phenylalanine. However, the requirements for histidine and arginine are frequently over
estimated and these AA`s should actually be considered semi-essential, which could
render methionine, leucine and phenylalanine the first three limiting AA`s to growing
lambs receiving high RDP diets. Because of the limitations of static measurement
systems for the determination of AA requirements, a more comprehensive evaluation
method was introduced for determination of the limiting AA`s in duodenal protein of
lambs on high RDP diets, in the fourth study.
The fourth study focused on the identification of limiting AA`s to growing lambs being
limit-fed a high RDP diet. The diet consisted primarily of soybean hulls, for its’ low
rumen UDP content. Microbial protein production was calculated as 13 % of total
digestible nutrient intake and complementary AA supplements prepared to simulate the
WEB AA profile, determined in the previous study, in the small intestine. To eliminate
the influence of the rumen on the AA supplements, the latter were infused into the
abomasums via flexible tubing. Each essential AA was in turn removed from the control
treatment (simulating the WEB composition) and the effect on N retention measured.
When methionine or the branched-chain amino acids (BCAA`s) were removed from the
infusate, N retention of the lambs was reduced. Consequently, methionine and at least
one of the BCAA`s limited growth performance of young lambs when microbial protein
was the predominant source of AA`s.
The concomitant increased plasma concentrations of total AA`s when methionine or the
BCAA`s were removed from the infusate corroborates the effects on N retention, since it
indicates that AA utilisation was reduced when these AA imbalances were introduced.
Amino acid imbalances had no effect on apparent DM, organic matter (OM) or NDF
digestion, but N digestibility was reduced. The final study verified whether the BCAA’s were co-limiting the growth of lambs, or if
any single BCAA was responsible for the limitation. Again the WEB AA profile of
growing lambs was simulated in the small intestine via abomasal infusions to lambs
receiving a soybean hull-based diet. Leucine, isoleucine and valine were individually or
simultaneously removed from the infusate and the impact on N retention measured. On
an individual basis valine had the largest negative impact on the efficiency of N
utilisation. However, the simultaneous removal of the BCAA`s resulted in the lowest N
retention, suggesting that valine might be limiting, but the three BCAA`s are more likely
to be co-limiting in diets to growing lambs where microbial protein is the primary source
of AA`s. Once again, neither DM, OM or NDF digestibility were affected by the AA
imbalances. Nitrogen digestibility was, however, negatively affected by AA imbalances.
This project succeeded in establishing the essential AA profile of duodenal protein in
sheep receiving high RDP diets. The WEB essential AA compositions of growing lambs
from two prominent sheep breeds in South Afica were then determined and the duodenal
essential AA profile evaluated against the calculated AA requirements. Finally, the AA`s
that limit growth in diets where microbial protein is the predominant source thereof were
identified. These results contribute to the current knowledge of AA requirements in
growing lambs, and highlight areas for future research, as discussed in the General
Conclusion
An evaluation of degradable protein and nonprotein nitrogen on intake and digestion by Dohne merino sheep fed wheat straw
Thesis (MSc)--Stellenbosch University, 2000.ENGLISH ABSTRACT: South Africa, like many other developing countries throughout the world, has a rapidly
growing human population, resulting in a consequent increased demand for food. Ironically,
this increased food supply has to be produced on a smaller area of available agricultural land,
which means that agricultural production processes have to become more efficient.
Furthermore, the majority of the people in these countries are unschooled and poverty is a
common phenomenon. Therefore, animal scientists are faced with the challenge and the
responsibility to provide affordable, high quality food to these people.
One way of reaching this objective is to improve the utilisation of low-quality, high roughage
feedstuffs like crop residues and dry natural grass pastures. In the winter rainfall area of
South Africa alone, about 460 000 ha of wheat straw are annually available. The ruminant
animal has the ability to utilise the relatively unavailable energy (cellulose, hemi-cellulose
and pectin) in the fibre component of these low-quality forages. Unfortunately, various
factors, of which a N deficiency is the pre-dominant one, limit the utilisation of these
feedstuffs. If the ability of the ruminant to utilise low-quality, fibrous energy sources is
improved, these abundantly available and relatively inexpensive crop residues and natural
pastures can be converted into high quality protein food for human consumption. Therefore, in order to rectify the N deficiency caused by these low-quality forages, the
supplemental N requirement to optimise the fermentation and digestive processes of the
ruminant animal has to be determined. The first study was conducted to determine the
supplemental rumen degradable protein (RDP) requirement, to maximise the digestible
organic matter intake (DOMI) of Dohne Merino sheep fed wheat straw. Keeping the high
cost of natural protein supplementation in mind, the purpose of the second study was to
determine the amount of true protein that can be replaced by nonprotein nitrogen (NPN) in
RDP supplements fed to Dohne Merino sheep consuming wheat straw.
In both trials animals had ad libitum access to low-quality wheat straw (3.2% CP;
74.2% NDF) and water. In the first trial, RDP (calsium caseinate: 90% CP; 100% rumen
degradable) was intraruminally administered at 07hOOand 19hOO,at the following levels: 0,
40,80, 120 and 160 gld. Intake, fermentation and digestion were monitored to determine the
RDP requirement to maximise DOM!. Digestible organic matter (OM) intake displayed a
quadratic increase with elevated amounts of RDP (P < .01), and was maximised at an
estimated 3.15 g RDPlkg BW·75 or 11.6% of DOM. Forage OM intake tended to increase
quadratically (P = .15) with higher RDP levels. Microbial nitrogen (MN) flow to the
duodenum and microbial efficiency increased quadratically (P ~ .04) and fluid dilution rate
tended to increase in a quadratic manner (P = .15) with increased RDP supplementation
levels. Rumina! ammonia nitrogen (NH3-N) and total volatile fatty acid (VFA)
concentrations increased linearly (P ~ .07), while rumen pH exhibited a variable response to
increased RDP levels (cubic; P = .08). Increasing RDP supplementation to Dohne Merino
wethers consuming wheat straw, generally enhanced forage utilisation and DOM!.
In the second trial, urea replaced different levels of casein N on an isonitrogenous basis,
ranging from 0 - 100%. Since true protein is much more expensive than urea, the purpose of
this study was to determine the maximum natural protein level that can be replaced by urea in
RDP supplements, without adversely affecting intake and/or fermentation and digestive
processes. The control treatment provided all of the RDP in the form of calcium caseinate
(90% CP; 100% rumen degradable). The percentages of supplemental RDP from urea in the
other treatments were 25, 50, 75 and 100%. The 100% urea treatment was balanced with
maize starch to contain 40% CP and all other treatments received the same amount (150 gld)
of starch. Intake of forage OM showed a weak decreasing trend (linear; P = .16) with increasing urea levels. Ruminal digestibilities of OM and NDF were not affected (P ;;::.:18) by
urea level. Increasing urea levels resulted in linearly reduced total tract OM and NDF
digestibilities (P ~ .10). As a result, DOMI declined (linear; P < .01) with increasing
proportions of urea. Effects of increasing urea proportions on duodenal N flow, microbial
efficiency and fluid dilution rate were minimal. Ruminal NH3-N tended to increase
quadratically with increasing urea levels (P = .l4). Total VFA concentration decreased
linearly (P = .03), while rumen pH increased in a linear manner (P = .08) with increasing
urea proportions. Branched-chain volatile fatty acids (BCVFA's) and valerate decreased
linearly (P ~ .05) with increasing urea levels, while other VFA's and the acetate:propionate
ratio were generally not affected by treatment (P ;;:::.16). It appears as though ruminal and
total tract OM and NDF digestibility criteria, as well as DOMI reached maximum values at
substituting 25% of casein for urea. It is therefore concluded that replacing 25% of casein
with urea in RDP supplements, will maintain effective utilisation of low-quality forages by
sheep.AFRIKAANSE OPSOMMING: Ontwikkelende lande, insluitend Suid-Afrika, word gekenmerk deur 'n vmmge
bevolkingsaanwas. Dit lei tot 'n verhoogde vraag na voedsel, wat op 'n gevolglik kleinerwordende
beskikbare kommersiële lanbbou-area geproduseer moet word. Die
doeltreffendheid van produksieprosesse in die landbousektor moet dus noodgedwonge
verbeter word. Die oorgrootte meerderheid van die bevolkings in ontwikkelende lande is
ongeletterd en armoede en hongersnood is soms 'n algemene verskynsel. Veekundiges word
dus gekonfronteer met die uitdaging en verantwoordelikheid om bekostigbare, hoë kwaliteit
voedsel aan hierdie mense te voorsien.
Een van die mees doeltreffende metodes om hierdie probleem aan te spreek, is om die
benutting van lae kwaliteit, hoë-vesel voerbronne, bv. oesreste en droë grasweidings te
verhoog. In die winterreënstreek van Suid-Afrika alleen, is 460 000 ha koringstrooi jaarliks
beskikbaar. Herkouers beskik oor die besondere vermoë om die relatief onbeskikbare energie
(sellulose, hemi-sellulose en pektien) in die veselkomponent van hierdie lae kwaliteit voere te
benut. Verskeie faktore, waarvan 'n N-tekort die mees prominente is, beperk egter die
benutting van hierdie voerbronne. Die uitdaging is dus om die herkouer se vermoë om
hierdie voere te benut, te optimaliseer. Sodoende word 'n geredelik beskikbare, onderbenutte
en relatief goedkoop voerbron omgeskakel in hoë kwaliteit proteïen vir menslike gebruik. Die N-aanvullingsbehoefte om die fermentasie- en verteringsprosesse van die herkouerdier te
optimaliseer moet dus bepaal word, sodat die N-tekort in herkouers, wat soortgelyke
weidings benut, reggestel kan word. Gevolglik was die doel met die eerste proef om die
behoefte aan rumen degradeerbare proteïen-(RDP)-aanvulling, vir die maksimum inname van
verteerbare organiese materiaal (VOM) van Dohne Merino skape wat koringstrooi ontvang,
te bepaal. Weens die hoë koste van natuurlike proteïenaanvulling, was die doel met die
tweede proef om die hoeveelheid ware proteïen in RDP-aanvullings, vir Dohne Merino skape
wat koringstrooi ontvang, wat met nie-proteïen stikstof (NPN) vervang kan word, te bepaal.
In beide eksperimente het die diere ad libitum toegang tot koringstrooi (3.2% RP;
74.2% NBV) en water gehad. In die eerste proefis RDP (kalsiumkaseïnaat; 90% RP; 100%
rumen degradeerbaar) teen 07hOOen 19hOOintraruminaal toegedien, teen die volgende peile:
0, 40, 80, 120 en 160 gld. Inname, fermentasie en vertering is gemonitor om die RDP
behoefte vir die maksimum inname van VOM te bepaal. Verteerbare OM-inname het 'n
stygende kwadratiese tendens (P < .01) getoon met verhoogde RDP-peile en het 'n
maksimum bereik by 'n aanvullingspeil van 3.15 g RDPlkg metaboliese liggaamsmassa
(LM·75
) of 11.6% van VOM. Organiese materiaalinname vanaf koringstrooi het geneig om
kwadraties toe te neem (P = .15) met verhoogde RDP-peile. Mikrobiese stikstof-(MN)-vloei
na die duodenum en mikrobiese effektiwiteit het kwadraties toegeneem (P :::;.;04) en vloeistof
deurvloeitempo het 'n neiging vir 'n kwadratiese toename (P = .15) met verhoogde RDPpeile
getoon. Rumen-ammoniakstikstof (NH3-N) en vlugtige vetsuur-(VVS)-konsentrasies
het lineêr toegeneem (P :::;.;07), terwyl rumen pH 'n wisselende reaksie (kubies; P = .08) met
stygende RDP-peile getoon het. Verteerbare OM-inname en benutting van koringstrooi is
verbeter deur stygende peile van RDP aanvulling by Dohne Merino hamels.
In die tweede proef is kaseïen op 'n iso-stikstof basis met verskillende ureumpeile, vanaf
o - 100%, vervang. Omdat ureum baie goedkoper is as natuurlike proteïen, was die doel van
die tweede proef om die hoeveelheid natuurlike proteïen in RDP-aanvullings te bepaal wat
met ureum vervang kan word, sonder om inname, fermentasie en vertering te benadeel. Die
kontrolebehandeling het 100% van die RDP in die vorm van kalsiumkaseïnaat (90% RP;
100% rumen degradeerbaar) voorsien, terwyl ureum in die ander behandelings onderskeidelik
25, 50, 75 en 100% van die kaseïen-N vervang het. Die 100% ureumbehandeling is met
mieliestysel tot 40% RP gebalanseer en dieselfde hoeveelheid stysel (150 gld) is by al die ander behandelings ingesluit, om moontlike effekte van stysel op rumenfermentasie te
elimineer. Organiese materiaalinname vanafkoringstrooi het 'n swak dalende tendens getoon
met stygende ureum insluitingsvlakke (lineêr; P = .16). Rumenverteerbaarheid van OM en
neutraal bestande vesel (NBV) is nie deur die ureumpeil beïnvloed nie (P ;;:: .18).
Toenemende ureumpeile het gelei tot 'n lineêre afname in totale kanaal OM en NBVverteerbaarheid
(P ~ .10). Gevolglik het VOM inname lineêr afgeneem (P < .01) met
stygende ureum insluitingspeile. Die effek van behandeling op duodenale N-vloei,
mikrobiese effektiwiteit en vloeistof deurvloeitempo was minimaal. Rumenammoniakstikstof-(
NH3-N)-konsentrasie het 'n stygende kwadratiese tendens getoon
(P = .14) met toenemende ureum peile. Totale vlugtige vetsuur-(VVS)-konsentrasies het
lineêr gedaal (P = .03), terwyl rumen pH lineêr toegeneem het (P = .08) met stygende ureum
insluitingsvlakke. Vertakte ketting VVS' e en valeriaansuurkonsentrasies het lineêr gedaal
(P ~ .05) met stygende ureumpeile, terwyl die ander VVS' e en die
asynsuur:propioonsuurverhouding oor die algemeen nie deur behandeling beïnvloed N; nie
(P ;;:: .16). Dit blyk asof VOM inname, sowel as rumen- en totale kanaal
verteerbaarheidsmaatstawwe, by 25% vervanging van kaseïen-N met ureum-N 'n maksimum
bereik het. Die gevolgtrekking is gemaak dat die doeltreffende benutting van lae kwaliteit
ruvoere deur skape, gehandhaaf sal word deur 25% van die ware proteïen in RDP-aanvullings
met ureum te vervang
Best practices for demand-driven supply chain management in public healthcare sector : a systematic literature review
CITATION: Bvuchete, M., Grobbelaar, S. S. & Van Eeden, J. 2020. Best practices for demand-driven supply chain management in public healthcare sector : a systematic literature review. South African Journal of Industrial Engineering, 31(2):11-27, doi:10.7166/31-2-2006.The original publication is available at http://sajie.journals.ac.zaENGLISH ABSTRACT: Healthcare supply chains ensure that there is a cost-effective availability of medicines at healthcare facilities. However, it appears that public healthcare supply chains in South Africa are experiencing significant challenges in the management and distribution of the right medicines, at the right time, and at the right cost. This has resulted in poor healthcare outcomes. Moreover, public health supply chains also face major challenges due to rising patient expectations and inefficiencies in supply chain operations. There is recent interest in increasing public health supply chain efficiency and improving patient services. To address these challenges and opportunities, other studies have suggested the transformation of healthcare supply chains from the current pure ‘push’ approach into a ‘pull’ approach, which is driven by actual customer demand (demand-driven supply chain management DDSCM). However, no guidelines exist to support the design of DDSCM in public healthcare supply chains. Therefore, through a systematic literature review, this study aims to distinguish the key success factors for the DDSCM approach from those of other industries, and subsequently develops a framework to guide the design of DDSCM for the public healthcare sector.http://sajie.journals.ac.za/pub/article/view/2006Publisher's versio
A concept demonstrator for self-organising demand-driven inventory management in pharmaceutical supply chains
CITATION: Du Plessis, M., Van Vuuren, J. H. & Van Eeden, J. 2018. A concept demonstrator for self-organising demand-driven inventory management in pharmaceutical supply chains. In SAIIE29 Proceedings, 24-26 October 2018, Spier, Stellenbosch, South Africa.The original publication is available at https://conferences.sun.ac.za/index.php/saiie29/saiie29/schedConf/presentationsENGLISH ABSTRACT: Perennial stock-outs of essential medicines are commonplace in the pharmaceutical supply chains of developing countries. Stock-outs are mainly attributed to a general lack of collective information sharing in pharmaceutical supply chains. In this paper, a computerised agent-based simulation model concept demonstrator is proposed and demonstrated hypothetically as part of a larger drive to establish the value of leveraging information sharing in pharmaceutical supply chains with a view to enhance decision-making. The objective of this paper is to outline the prerequisite research inputs, design requirements and hypothetical implementation of the aforementioned demonstrator. The work reported on in this paper remains a work in progress.https://conferences.sun.ac.za/index.php/saiie29/saiie29/paper/view/3633Publisher's versio
Hospital inventory management : a systematic review of the literature
CITATION: Higgo, M. R., Grobbelaar, S. S. & Van Eeden, J. 2018. Hospital inventory management : a systematic review of the literature. In SAIIE29 Proceedings, 24-26 October 2018, Spier, Stellenbosch, South Africa.The original publication is available at https://conferences.sun.ac.za/index.php/saiie29/saiie29/schedConf/presentationsHospitals and clinics provide an essential service to the populace, assisting people to overcome a range of ailments. In order to do so physicians are reliant on the tools and inventory they have at their disposal. When stock levels appear frighteningly low or even become depleted, physicians begin to order more than the ideal amount causing overstocking and consequently, wastage. This paper performs a systematic literature review in order to identify the causes for the unsatisfactory inventory management currently experienced in South African healthcare facilities.https://conferences.sun.ac.za/index.php/saiie29/saiie29/paper/view/3570Publisher's versio