With Industry 4.0, companies are faced with the challenge of managing an ever-increasing amount of data and re-evaluating and innovating their production planning methods. An important aspect of demand forecasting is the accuracy of forecasts compared to outcomes. Research has shown that more complex models perform better in demand forecasting, however, this research has focused on demand forecasting in the IT, finance and e-commerce sectors.   This thesis investigates the application of predictive modelling in demand forecasting in the context of production planning for a medium-sized manufacturing company. The study mainly compares the performance of two predictive models: Autoregressive Integrated Moving Average (ARIMA) and Long Short-Term Memory (LSTM) networks, with the aim of assessing its usefulness in improving the accuracy of demand forecasts. Based on historical sales data, this quantitative case study investigates how these models can improve operational efficiency that can be applied to production planning processes such as optimal inventory and production schedules.    The study found that the LSTM model, through Automated Machine Learning (AutoML), was significantly better than the ARIMA model in terms of forecast accuracy. This was evidenced by lower Root Mean Squared Error (RMSE) and Mean Absolute Error (MAE) values, indicating that LSTM's ability to capture long-term dependencies and adapt to non-linear patterns provides a more robust tool for demand forecasting in production planning.   This study contributes to the field of industrial engineering by demonstrating the practical benefits of integrating advanced predictive models into manufacturing companies' production planning processes. It highlights the potential of machine learning techniques to transform traditional production planning systems and thus provides insights into the strategic implementation of AI in industrial operations. Future research could explore and compare more models to get a broader picture of how different models perform against each other in terms of prediction errors. / Med Industri 4.0 står företagen inför utmaningen att hantera en ständigt ökande mängd data och att omvärdera och förnya sina metoder för produktionsplanering. En viktig aspekt av efterfrågeprognoser är prognosernas träffsäkerhet jämfört med utfallet. Forskning har visat att mer komplexa modeller presterar bättre vid efterfrågeprognoser, men denna forskning har fokuserat på efterfrågeprognoser inom IT-, finans- och e-handelssektorerna.   Denna studie undersöker tillämpningen av prediktiv modellering vid efterfrågeprognoser i samband med produktionsplanering för ett medelstort tillverkningsföretag. Studien jämför främst prestandan hos två prediktiva modeller: Autoregressive Integrated Moving Average (ARIMA) och Long Short-Term Memory (LSTM) nätverk, i syfte att bedöma hur användbara de är för att förbättra precisionen i efterfrågeprognoser. Baserat på historiska försäljningsdata undersöker denna kvantitativa fallstudie hur dessa modeller kan förbättra den operativa effektiviteten som kan tillämpas på produktionsplaneringsprocesser, såsom lagerhållning och produktionsscheman.    Studien visade att LSTM-modellen, genom automatiserad maskininlärning (AutoML), var betydligt bättre än ARIMA-modellen när det gäller prognosprecision. Detta framgick av lägre RMSE-värden (Root Mean Squared Error) och MAE-värden (Mean Absolute Error), vilket tyder på att LSTM:s förmåga att fånga upp långsiktiga beroenden och anpassa sig till icke-linjära mönster ger ett mer robust verktyg för efterfrågeprognoser inom produktionsplanering.   Denna studie bidrar till området industriell ekonomi genom att visa på de praktiska fördelarna med att integrera avancerade prediktiva modeller i tillverkningsföretagens produktionsplaneringsprocesser. Den belyser maskininlärningsteknikernas potential att omvandla traditionella produktionsplaneringssystem och ger därmed insikter i den strategiska implementeringen av AI i industriell verksamhet. Framtida forskning skulle kunna utforska och jämföra fler modeller för att få en bredare bild av hur olika modeller presterar mot varandra när det gäller prediktionsfel.

Thesis (MBA)--Stellenbosch University, 2007. / ENGLISH ABSTRACT: Diamond mining started in Kimberley in the early 1870s following the discovery of the various diamond bearing kimberlite pipes. Initial open pit mining was replaced by underground mining as the pits went deeper and the last underground mining eventually ceased in 2005 as a result of economic reasons. The mining of these primary resources created a number of tailing resources (previously called dumps) that are scattered all over Kimberley. These resources still contain diamonds as a result of historical inefficient processing technologies. However, each of these resources have unique geological and metallurgical properties because of the differences in the original kimberlites and the different treatment technologies that were used when the tailing resources were deposited. The tailing resources are mined by a fleet of earthmoving equipment and delivered to one of Kimberley Mines‟ five treatment plants for diamond recovery. Each plant is different in terms of treatment capacity, technologies utilised and overall efficiencies. These differences, combined with the geo-metallurgical properties of each individual resource and the hauling distance from the resource to the plant, determine if the specific resource can be treated profitably through that plant. With this array of resources available, Kimberley Mines is in the fortunate position of having flexibility to maximise the Net Present Value (NPV) of the operation. Unfortunately this flexibility also increases the complexity of finding the optimal solution. Mine Planning is currently conducted with a spreadsheet based input – output model but this model is not able to match the resource properties with the plant parameters and this method results in a plan that may be neither practical nor optimal. The model is also very time-consuming and scenario analyses are therefore very limited. This report presents the development of a mixed integer linear programming model to assist with the development of a practical, optimal mine plan. The model is roughly based on a generic model that addresses facility location and processing plant problems as developed by Barbaro & Ramani (1986); however, the model presented in this report includes a more detailed mass balance within the plant and models how the metallurgical properties of the resources affect the mass balances and overall throughputs. The results of the project indicate that the current spreadsheet based Mine Plan is not practical since it violates two mass balance constraints within the Combined Treatment Plant. The newly developed system is used to generate a mining schedule that does not violate any constraints while still delivering the same net present value and overall throughput. The system also illustrates that the plant can improve the annual throughput by 18.2% by changing one screen size. The system also illustrates that only two of the five plants add value and supports management‟s recent decision that the production through the other plants should cease. In summary: The newly developed system generates an optimal, practical mine plan in less than a tenth of the time required for the old spreadsheet based model. The new system can also do various what-if scenarios which the previous model could not answer. / AFRIKAANSE OPSOMMING: Die ontginning van diamante in Kimberley het in die vroeë 1870s begin na die ontdekking van verskeie diamanthoudende kimberlietpype. Aanvanklike oopgroefmynbou is later vervang deur ondergrondse metodes soos die myne dieper geword het. Die laaste ondergrondse myne het in 2005 produksie gestaak as gevolg van ekonomiese redes. Die ontginning van hierdie primêre reserwes het gelei tot die ontstaan van verskeie uitskotreserwes (voorheen genoem afvalhope) verspreid oor Kimberley. Hierdie reserwes bevat steeds diamante as gevolg van die historiese oneffektiewe aanlegte. Die reserwes het elkeen egter verskillende geologiese en metallurgiese eienskappe as gevolg van die verskille in die oorspronklike kimberliete en die verskillende herwinningstegnologieë wat in gebruik was toe die uitskotreserwes gegenereer is. Die uitskotreserwes word gemyn deur ‟n vloot grondverskuiwingstoerusting en word afgelewer by een van Kimberley Myne se vyf aanlegte vir diamantherwinning. Elke aanleg is uniek in terme van kapasiteit, tegnologieë in gebruik en algehele effektiwiteit. Hierdie verskille, tesame met die geo-metallurgiese eienskappe van elke reserwe en die vervoerafstand van die reserwe na die aanleg bepaal of die spesifieke reserwe winsgewend deur daardie aanleg geprosesseer kan word. Bogenoemde verskeidenheid van hulpbronne gee aan Kimberley Myne die voordeel van buigsaamheid om die Netto Huidige Waarde (NHW) van die myn te maksimeer. Hierdie buigsaamheid vergroot egter die kompleksiteit om die optimale antwoord te vind. Beplanning word tans met ‟n sigblad gebasseerde invoer – uitvoer model gedoen, maar hierdie model is nie in staat om die reserwes se eienskappe by die aanlegte se parameters aan te pas nie. Hierdie metode genereer dus ‟n plan wat moontlik nie prakties of optimaal is nie. Die model is ook tydrowend en scenario analises is dus baie beperk. Hierdie verslag beskryf die ontwikkeling van ‟n gemengde heeltallige lineêre programmeringsmodel vir die ontwikkeling van ‟n praktiese, optimale produksieplan. Die model is losweg gegrond op ‟n generiese model van Barbaro & Ramani (1986) wat fasiliteit posisionering en aanlegprobleme aanspreek. Die model in hierdie verslag bevat egter ‟n meer gedetailleerde massabalans binne die aanleg en modelleer hoe die metallurgiese eienskappe van die reserwes die massabalanse en die algehele kapasiteite beïnvloed. Die resultate van die projek dui daarop dat die huidige sigblad produksieplan nie prakties is nie aangesien dit twee massabalansbeperkings in die Combined Treatment Plant oorskry. Die nuwe stelsel is gebruik om ‟n produksieskedule te genereer wat nie enige beperkings verbreek nie en wat terselfdertyd die aanvanklike netto huidige waarde en totale produksie ewenaar. Die stelsel wys ook dat die jaarlikse kapasiteit met 18.2% verhoog kan word deur een van die sif-groottes te verander. Die stelsel demonstreer ook dat slegs twee van die vyf aanlegte waarde toevoeg en ondersteun bestuur se onlangse besluit dat die produksie deur die ander aanlegte gestaak behoort te word. Ter samevatting: Die nuwe stelsel genereer ‟n optimale, praktiese produksieplan in minder as ‟n tiende van die tyd benodig vir die ou sigblad model. Die nuwe stelsel kan ook verskeie “Wat sal gebeur indien…” scenario‟s hanteer wat die vorige model nie kon beantwoord nie.

In the present electrical market there is an increasing penetration of intermittent energy sources. Several studies have examined its effect on the planning of hydropower operation and the conclusion is that an increasing intermittent production is likely to result in a more variable hydropower operation, utilising a wider span of operational set points. The wear of a hydropower unit is generally at a minimum when operated close to best efficiency and increases when operating at higher or lower set points. This study introduces a method to calculate an operation dependent cost (ODC) function for an arbitrary hydropower unit or unit combination based on vibration measurements and operational data. The method is tested in a case study where an ODC is implemented in Akkats, located in the Small Lule River in order to evaluate its effect on operational pattern, profitability and balancing contribution. The results show that the implemented ODC mainly affects Akkats. For an increasing ODC, Akkats is operated closer to the best point of efficiency and the operational pattern gets less variable and the effect gets more apparent the lower the spot price. Akkats ability to follow the spot price is reduced, decreasing the earning per produced energy with a few percent­ages. Akkats balancing contribution decreases significantly more, due to a less variable operational pattern. The study compares the reduced ODC to the reduced spot income and concludes that the wear cost in Akkats has to be above 1,21 €/MWh in order to be economically feasible to include in the planning. The operational pattern for the simulated river is close to unchanged at highest price hours but during lower price hours an increasing ODC results in an increased production, due to an increasing mean flow and changed operational pattern in Akkats. More production during low prices hours results in a decreasing profitability for all plants along the river. The balancing contribution is close to unchanged in all plants except Akkats, since the production still follows the same pattern.

Thesis (MBA (Business Management))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: The aim of this paper was to prove the contribution of the Works Order Close-Out Meeting process at Nampak Flexible Ndabeni, through the development of a Close-Out Meeting contribution evaluation model. Although the value of the Close-Out Meeting process is intuitively understood, a formal measurement would underscore the importance of the process. Using a funnel-based analysis, a total of 63 Close-Out Meeting findings was identified for formal benefit review and were categorised into five finding groups. For each of these five groups a contribution measurement methodology was developed. The methodology was rooted in sound management and ERP theory and then applied to the findings in each group. The following key groups were identified and discussed: Incorrect standards. The importance of correct standards was shown, and the potential misstatement due to incorrect standards was quantified. The analysis showed that effective, ongoing variance review can identify errors in standards and that changes can be initiated and authorised in a short timeframe. ERP process review. Findings that specifically addressed lack of proper process were reviewed and real benefit was calculated for three categories, namely information misstatement, risk mitigation and productivity gains. Formulas were developed and applied for the benefit calculation. The analysis showed it is dangerous to assume that processes are cast in stone or fundamentally sound, and that the Close-Out review process not only identifies deficiency of these processes, but initiates corrective action. Shop floor process review. The investigation into findings that addressed process conformance showed that in most cases the process breakdowns related to the accuracy of information captured into the ERP. The impact of poor information, process non-conformance and corrective action was clearly shown. Actions to improve performance. Targeted actions to improve production performance were subdivided into actions that improved productivity and actions that reduced the risk of recurrence of a negative event. Benefits were calculated using established methods, and in both cases the benefit was substantial. Business decision confirmation. The Close-Out Meeting sometimes forced analysis that did not lead to action but to a better understanding of the business reality. What was shown is that the ability to identify, list and analyse findings of this nature added value. By expanding the benefit analysis beyond a simplistic implementation of corrective action, the scope of benefits was increased. The study achieved several objectives. The analysis showed that corrective actions taken by management have a scientific base and that the implementation of corrective actions delivered real business value. This allowed the business to place the Close-Out Meetings in the correct context, as the business could conclude that Close-Out Meetings were fundamental to its continued success. From a theoretical point of view the body of knowledge around Close-Out Meetings was expanded, while the results also supported the Nampak ERP value case. Close-Out Meetings at Nampak Flexible delivered clear, measurable benefits when discussion points were converted to actions that were acted upon by the business. The value was of such a nature to confirm the importance of Close-Out Meetings as a component of good ERP-manufacturing practice. / AFRIKAANSE OPSOMMING: Die doel van hierdie werkstuk was om die bydrae van die "Works Order Close-Out Meeting" proses by Nampak Flexible Ndabeni te bewys met behulp van 'n "Close-Out Meeting" evaluasiemodel. Alhoewel die waarde van die "Close-Out Meeting"-proses intuitief aanvaar word, aksentueer die ontwikkeling van 'n formele maatstaf die belangrikheid van die proses. 'n Evaluasieproses het 'n totaa1 van 63 bevindinge opgelewer vir analise. Die bevindinge is ingedeel in vyf groeperings en vir elke groepering is 'n ste1 maatstawwe ontwikkel ten einde die bydrae van die bevindinge te meet. Hierdie maatstawwe was gebaseer op bestaande, aanvaarde ERP- en bestuursteorie. Die volgende vyf groepe was geidentifiseer en bespreek. Foutiewe standaarde. Die belangrikheid van akkurate standaarde in die stelsel is bewys, en die skaal van informasiefoute as gevolg van verkeerde standaarde is gekwantifiseer. Daar is bewys dat effektiewe, voortdurende variasie-analise foute kan identifiseer en dat die nodige korrektiewe aksie vinnig implementeerbaar is. ERP-proses. Bevindinge wat voortspruit uit swak prosesse is geidentifiseer en die waarde van die korrektiewe aksie is op drie vlakke geanaliseer, naamlik informasiefoute, risikobeheer en produktiwiteitsverbetering. Formules is ontwikkel en toegepas om die waarde van die korrektiewe aksie te bepaal. Daar is bewys dat dit gevaarlik is om aan te neem dat besigheidsprosesse fundamenteel korrek is, en dat die "Close-Out Review"-proses nie net foutiewe prosesse uitgewys het nie, maar ook die nodige korrektiewe aksie gedryf het. Fabrieksvloerproses. Die ondersoek na bevindinge wat prosesafwykings uitgewys het, het aangedui dat afwykings meestal voorgekom het as gevolg van foutiewe informasie in die ERP-stelsel. Die impak van foutiewe informasie, prosesafwykings en inisiatiewe om die akkuraatheid van informasie te verbeter is duidelik gewys. Produksieverbetering. Bevindinge wat gelei het tot inisiatiewe om produksie te verbeter is verdeel tussen produktiwiteitsverbetering en risikobeheer. Die waarde van die inisiatiewe is bereken met die gebruik van ontwikkelde metodes en in beide gevalle was die resultate baie positief. Ondersteuning by besluitneming. Die "Close-Out Meeting"-proses het somtyds gely tot analise wat nie aanieiding gegee het tot korrektiewe aksie nie, maar wel daartoe gelei het dat bestuur se begrip van besigheidsrealiteit verbeter het. Daar is bewys dat 'n proses wat besigheidsinformasie aan bestuur kan weergee ter ondersteuning van bestuursbesluite, waardevol is. Die mate van voordeel wat uit die proses stem is vergroot deur die waarde-analise uit te brei sodat dit meer is as die blote analise van korrektiewe aksie. Die berekende voordeel uit die "Close-Out Meeting"-proses is groter wanneer die hestek van die voordeel vergroot word om meer as net die direkte waarde van korrektiewe aksie in te sluit. Die studie het voldoen aan verskeie doelwitte. Daar is bewys dat bestuursaksie 'n wetenskaplike basis het en die uitvoer van hierdie aksies besigheidswaarde toevoeg. As gevolg hiervan kon die besigheid "Close-Out Meetings" in die regte konteks plaas en tot die slotsom kom dat hierdie proses 'n fundamentele drywer van besigheidsukses is. Ten slotte is die teorie oor "Close-Out Meetings" uitgebrei en die resultate het ook die waarde onderskryf wat Nampak uit sy ERP-implementasie gekry het. "Close-Out Meetings" by Nampak Flexible het duidelike meetbare voordele opgelewer wanneer die probleme wat geidentifiseer is gelei het tot korrektiewe aksie. Die waarde was van so 'n aard dat die belangrikheid van "Close-Out Meetings" as 'n komponent van goeie vervaardigingsbestuur in 'n ERP-konteks duidelik bewys is.

The global competitive environment and the growing demand for personalised products have increased the interest of companies in producing similar product models on the same assembly line. Companies are forced to make significant structural changes to rapidly respond to diversified demands and convert their existing single-model lines into mixed-model lines in order to avoid unnecessary new line construction cost for each new product model. Mixed-model assembly lines play a key role in increasing productivity without compromising quality for manufacturing enterprises. The literature is extensive on assembling small-sized products in an intermixed sequence and assembling large-sized products in large volumes on single-model lines. However, a mixed-model parallel two-sided line system, where two or more similar products or similar models of a large-sized product are assembled on each of the parallel two-sided lines in an intermixed sequence, has not been of interest to academia so far. Moreover, taking model sequencing problem into consideration on a mixed-model parallel two-sided line system is a novel research topic in this domain. Within this context, the problem of simultaneous balancing and sequencing of mixed-model parallel two-sided lines is defined and described using illustrative examples for the first time in the literature. The mathematical model of the problem is also developed to exhibit the main characteristics of the problem and to explore the logic underlying the algorithms developed. The benefits of utilising multi-line stations between two adjacent lines are discussed and numerical examples are provided. An agent-based ant colony optimisation algorithm (called ABACO) is developed to obtain a generic solution that conforms to any model sequence and it is enhanced step-by-step to increase the quality of the solutions obtained. Then, the algorithm is modified with the integration of a model sequencing procedure (where the modified version is called ABACO/S) to balance lines by tracking the product model changes on each workstation in a complex production environment where each of the parallel lines may a have different cycle time. Finally, a genetic algorithm based model sequencing mechanism is integrated to the algorithm to increase the robustness of the obtained solutions. Computational tests are performed using test cases to observe the performances of the developed algorithms. Statistical tests are conducted through obtained results and test results establish that balancing mixed-model parallel two-sided lines together has a significant effect on the sought performance measures (a weighted summation of line length and the number of workstations) in comparison with balancing those lines separately. Another important finding of the research is that considering model sequencing problem along with the line balancing problem helps algorithm find better line balances with better performance measures. The results also indicate that the developed ABACO and ABACO/S algorithms outperform other test heuristics commonly used in the literature in solving various line balancing problems; and integrating a genetic algorithm based model sequencing mechanism into ABACO/S helps the algorithm find better solutions with less amount of computational effort.

Cementproduktion står idag för totalt 5 % av koldioxidutsläppen globalt, vilket t.ex. är mer än dubbelt så mycket som den globala flygindustrin. Nya cement- och betongrecept, med nya egenskaper, utvecklas med målet att minska klimatbelastningen. I produkten Bascement ersätts delar av klimatbelastande cementklinker med mineraltillsatsen flygaska, en restprodukt från andra industrier. Detta ska alltså leda till en minskad klimatbelastning. Betong med Bascement har dock orsakat förseningar och extra kostnader i produktion på grund av långa torktider som inte stämt överens med simuleringar i TorkaS 3.2, en programvara baserad på betong med Byggcement. TorkaS ska ersättas av programvaran Produktionsplanering Betong (PPB) som kan simulera uttorkning i betong med Bascement. Målet med studien är att undersöka hur fuktsimuleringar i PPB skiljer sig jämfört med genomförda fuktmätningar i fyra betongprover med två olika vattencementtal, vct. Genom att förvara proverna i olika miljö är målet att experimentellt mäta hur omgivningen påverkar uttorkningen. Målet är vidare att visa skillnader mellan fuktsimuleringar med inbyggd klimatdata i PPB och med egna uppmätta klimatdata. Resultaten från de experimentella undersökningarna visar att uttorkningen blev större i betongprover med vct 0,40 än för motsvarande prover med vct 0,55 efter 70 dagar. Prover som hade förvarats i en stabil inomhusmiljö hade torkat mer än prover som hade förvarats i en varierande utomhusmiljö, vilket i denna studie inte stämde överens med simuleringar i PPB. Resultatet i denna studie visar att simuleringar i PPB tenderar att visa något större uttorkning jämfört med genomförda fuktmätningar. Denna överskattning blir större vid simuleringar med en varierande utomhusmiljö än med en stabil inomhusmiljö. Överskattningen blir större vid simuleringar med inbyggd klimatdata i PPB än med egna uppmätta klimatdata. Vid justering av betongens maxtemperatur i PPB till verkligt uppmätt maxtemperatur påverkas fuktsimuleringarna positivt så att de närmar sig de experimentellt erhållna resultaten. Betong med låga vct påverkas mer av en sådan justering än höga vct. Slutsatsen i denna studie är baserad på simuleringar och fuktmätningar i ett fåtal betongprover, vilka kan ha utsatts för störningar. Fler studier behövs för att validera reliabiliteten hos programvaran PPB. Val av härdningsmetod samt maxtemperatur under härdning kan påverka uttorkningen och simuleringar i PPB. Experimenten indikerar att simuleringar med PPB tenderar att avvika om betong med höga vct utsätts för vattentillskott kort efter gjutning. Korrekt maxtemperatur i PPB är viktigt för en mer verklig simulering av uttorkning i betong, särskilt vid låga vct. Simuleringar i PPB tenderar att bli mer korrekta med egna klimatdata än med inbyggd klimatdata. / Cement production currently accounts for a total of 5 % of carbon dioxide emissions globally, which for example is more than twice as much as the global aviation industry. New cement and concrete recipes, with new properties, are being developed with the aim of reducing the climate load. In the Portland fly ash cement, parts of climate-stressing cement clinkers are replaced with the mineral-added fly ash, a residual product from other industries. This should lead to a reduced climate impact. Concrete with Portland fly ash cement, however, has caused delays and extra costs in production due to long drying times that did not match with simulations in the software TorkaS 3.2, which is based on concrete with Portland-limestone cement. TorkaS will be replaced by the software Production Planning Concrete, PPB, which can simulate dehydration in concrete with Portland fly ash cement. The aim of the study is to investigate how moisture simulations in PPB differ from executed moisture measurements in four concrete samples with two different w/c ratio. By storing the samples in different environments, the goal is to experimentally measure how the environment affects the dehydration. The goal is also to show differences between moisture simulations with the built-in climate data in PPB and with the own measured climate data. The results from the experimental studies show that the dehydration became larger in concrete samples with w/c ratio 0.40 than for samples with w/c ratio 0.55 after 70 days. Samples that had been stored in a stable indoor environment had dried more than samples that had been stored in a varying outdoor environment, which in this study did not correspond to simulations in PPB. The result of this study shows that simulations in PPB tend to show slightly greater dehydration than executed moisture measurements. This overestimation is greater in simulations with a varying outdoor environment than with a stable indoor environment. The overestimation is greater in simulations with the built-in climate data in PPB than with the own measured climate data. When adjusting the maximum temperature of the concrete in PPB to the actual measured maximum temperature, the moisture simulations is positively affected so that they approach the experimentally obtained results. Concrete with low w/c ratio is more affected by such an adjustment than concrete with high w/c ratio. The conclusion in this study is based on simulations and moisture measurements in a few concrete samples, which may have been exposed to disturbances. More studies are needed to validate the reliability of the PPB software. Choice of curing method and maximum temperature during curing can affect the drying and simulations in PPB. The experiments indicate that simulations with the PPB software tend to deviate if concrete with a high w/c ratio is exposed to water shortly after casting. Correct maximum temperature in PPB is important for a more real simulation of dehydration in concrete, especially at high w/c ratio. Simulations in PPB tend to be more accurate when using own climate data than using the built-in climate data.

Produktivitetsutvecklingen i byggbranschen är låg jämfört med många andra branscher. Stigande produktivitet är en förutsättning för en fortgående ökning av en organisations tillväxt. Arbetsproduktiviteten i byggproduktionen kan ses som en grov uppskattning av den totala produktiviteten, där byggnadsarbetarens arbetstid blir en spegling av hur väl projektorganisationen, produktionsledningen och produktionsplaneringen fungerar i verksamheten. Syftet med detta examensarbete är att ta reda på de mest bidragande faktorerna som påverkar arbetsproduktiviteten i byggproduktionen samt att kartlägga hur de olika faktorerna upplevs hos det undersökta byggföretaget. Vidare undersöks vilka samband det finns mellan de olika faktorerna och dess bakomliggande orsaker med fokus på den dagliga verksamheten. Målet är att ta reda på förbättringsåtgärder gällande arbetsmetodik för ett produktivt arbete. Frågorna som besvarades i detta examensarbete var vilka faktorer som är mest bidragande till arbetsproduktiviteten i byggproduktionen, hur byggnadsarbetare och tjänstemän på företaget upplever de undersökta faktorerna samt vilka förbättringsåtgärder företaget ska arbeta med som leder till en ökad arbetsproduktivitet. De metoder som använts i forskningsrapporten är dels en litteraturstudie som tagit reda på vilka faktorer som bidrar mest till arbetsproduktiviteten i byggfasen. Efter detta gjordes en ytterligare undersökning på varje faktor med syftet att ta reda på vilka delfaktorer som påverkar den undersökta faktorn. Därefter utfördes en enkätstudie som var uppbyggd utefter de olika faktorerna. 51 byggnadsarbetare och 17 tjänstemän medverkade i studien. Därpå gjordes en sammanställning av enkätsvaren som sedan analyserades. Resultatet visar att de mest bidragande faktorerna som påverkar arbetsproduktiviteten är arbetsmiljö, produktionsplanering, kommunikation, motivation och engagemang. Den generella bilden över hur byggnadsarbetare och tjänstemän på företaget upplever de olika faktorerna är positiv. De mest prioriterade förbättringsåtgärderna som företaget bör prioritera att förbättra för att optimera arbetsproduktiviteten är följande: genomtänkt tidsplanering, resursplanering efter bästa lag, materialbeställning i rätt tid, involvera byggnadsarbetare i arbetsberedningar, att byggnadsarbetare får utbildningar som ökar deras kompetens, att platsledningen är ute oftare på byggarbetsplatsen och styr bygget, att informera om nästa arbetsuppgift i god tid, att byggnadsarbetare får en högre lön samt att få beröm från chefen. / Productivity development in the construction industry is low compared to many other industries. Rising productivity is a prerequisite for an ongoing increase in the growth of an organization. Work productivity in construction work can be seen as a rough estimate of total productivity, where the construction worker's working time becomes a reflection of how well the project organization, production management and production planning work in the business. The purpose of this thesis is to find out the most contributing factors that affect work productivity in construction production and to map how the various factors are experienced at the company that being examined. Furthermore, the connections between the various factors and their underlying causes with a focus on daily activities are examined. The goal is to find out improvement measures regarding work methodology for productive work. The questions that were answered in this thesis were which factors contributed most to work productivity in construction work, how construction workers and officials at the company perceive the factors examined and what improvement measures the construction company should work with that leads to increased work productivity. The methods used in the research report are partly a literature study that has identified which factors contribute most to work productivity in the construction phase. After this, a further study was done on each factor with the aim of finding out which sub-factors affect the examined factor. Then, a questionnaire study was carried out that was structured according to the various factors. 51 construction workers and 17 officials participated in the study. Then a survey of the questionnaire responses was made, which was then analyzed. The result shows that the most contributing factors that affect work productivity are work environment, production planning, communication, motivation and commitment. The general picture of how construction workers and officials at the company experience the different factors is positive. The most prioritized improvement measures that the company should prioritize in order to optimize work productivity are the following: well thought-out time planning, resource planning according to team best team, ordering material at the right time, involving construction workers in work preparations, that construction workers receive education that increases their competence, that the site management is out more often at the construction site and controls the work, to inform about the next task in good time, that construction workers receive a higher salary and to receive praise from the boss.

As decisões operacionais de produção em uma indústria de fiação são planejadas na prática determinando soluções dos sub-problemas de dimensionamento e sequenciamento de lotes e da mistura de fardos de algodão. As tarefas são: definir o tamanho, a sequência, o tempo e alocação de cada lote de produção e quais fardos de algodão devem ser utilizados na produção. Por si só, os sub-problemas representam grandes desafios no planejamento da produção. Entretanto, para melhor representar o ambiente produtivo e alcançar custos de produção mais baixos, indústrias de processo, como as de fiação, procuram integrar mais e mais seus sub-problemas de planejamento. O objetivo dessa tese é apresentar modelos matemáticos e métodos de solução para auxiliar a tomada de decisão no nível operacional do planejamento da produção. Três formulações matemáticas para o dimensionamento e sequenciamento de lotes em um sistema de dois estágios com produção sincronizada são propostas. Um novo método baseado em programação matemática e metaheurísticas e também desenvolvida para a solucão desse sub-problema. Além disso, a integração das decisões relativas a matéria-prima (fardos de algodão) ao dimensionamento e sequenciamento de lotes é analisada. As novas formulações propostas representam de forma mais realista o problema de dimensionamento e sequenciamento de lotes da indústria de fiação e de indústrias de processo com ambiente produtivo similares. O método de solução encontra boas soluções para o problema e supera outros méodos similares presentes em softwares comerciais. Além disso, o método é geral o suficiente para a solução de outros problemas de otimização. O problema integrado de dimensionamento e sequenciamento de lotes e mistura comprovou que restrições relativas à qualidade dos fios influenciam os custos e viabilidade do planejamento da produção. O planejamento integrado dessas óperações trata o sistema considerando restrições que se relacionam, definindo planos de produção mais realistas / In the practice of a spinning industry, the operational decisions of the production planning are determined by the hierarchical solution of the lot-sizing and scheduling problem and the blending problem of the cotton bales. The tasks are: to define the size, sequence, timing and allocation of each production lot and to select which cotton bales are used for production. Each of these problems represents a large challenge in planning the production. However, in order to better represent the production environment and to reach lower production costs, process industries (as the spinning industry) are integrating more and more of the production sub-problems into the planning. The aim of this thesis is to propose novel mathematical models and solution methods to assist the decision maker to plan the production at the operational level. Three formulations for the synchronized two-stage lot sizing and scheduling are proposed. A new method based on mathematical programming and metaheuristics is also developed to solve this sub-problem. In addition, the integration of the lot sizing and scheduling with decisions related to the raw materials (cotton bales) is analyzed. The novel models represent a more realistic lot sizing and scheduling for the spinning industry and process industries of similar production environment. The solution method finds good solutions to the mentioned problem and outperforms other state-of-the-art methods incorporated in commercial softwares. Moreover, the method is general enough to solve other optimization problems. The integrated lot-sizing, scheduling and blending prove that constraints related to the yarn quality influence the costs and the feasibility of the production planning. The integrated planning of these operations approaches the system considering the constraint relationship and defines more realistic production plans

Uma rede de cooperação entre empresas é definida como um grupo de empresas que interagem entre si pela troca de competências, de forma a atender uma série de suas necessidades que seriam de difícil satisfação no caso de atuarem isoladamente. Tendo em vista que o planejamento e controle da produção possui importância de primeira grandeza dentro da empresa industrial como da rede de cooperação, e que, através da modelagem organizacional, pode-se observar as empresas com uma maior e melhor dimensão de entendimento, permitindo a integração dos seus componentes. Este trabalho tem o objetivo de adequar o PCP ao ambiente de redes de cooperação entre empresas, por meio da utilização da metodologia de modelagem organizacional (EKD) e de um estudo de caso em obra de construção civil / An interorganizational cooperation network is defined as a group of companies which interact among themselves for exchange of competences, so a series of necessity from the companies which would be a difficult satisfaction if the work were done individually. In view of that the production planning and control has a great importance in an industrial company and also in the cooperation network. Through organizational modeling, can be observed the company with a greater and better dimension of agreement, which allows the integration of the companies’ components. This work has the objective to adjust the PPC to the environment of cooperation networks between companies, once several resources, capacities and ability are congregated and must be endeavored by a flow of information, through the use of the methodology of organizational modeling (EKD) and case study in workmanship of civil construction

O ambiente competitivo atual tem colocado pressão no processo de tomada de decisão no mundo corporativo. Os trade-offs das prioridades competitivas discutidos na elaboração da estratégia como custo, qualidade, serviço e flexibilidade já não são suficientes. Estes trade-offs, embora importantes no curto prazo, devem ser compatibilizados de modo que as empresas que tenham o melhor balanço entre eles devam ter resultado superior. Um dos trade-offs bastante discutido é o equilíbrio entre serviço e estoque. A percepção é que seja improvável alcançar excelência no serviço sem ter um considerável nível de estoque. Deste cenário nasce então o paradoxo do uso de sistemas MRP (Material Requirement Planning) versus sistemas JIT (Just in Time), ou melhor, sistemas empurrados versus puxados, já que a escolha por um ou outro sistema tem ligação íntima com a gestão de estoque. Se por um lado os sistemas MRP são largamente utilizados, via softwares ERP, por outro sistemas JIT têm trazido importantes melhorias nos resultados. Embora muitas empresas considerem a adoção exclusiva de um ou outro sistema, algumas delas têm adotado um processo híbrido com o objetivo de tirar o melhor de cada sistema e gerar assim desempenho superior. O objetivo deste trabalho é investigar como as empresas inseridas em mercados caracterizados pela concentração de demanda no final do mês (fenômeno conhecido como hockey-stick), e baixo acerto nas previsões de demanda, estão aplicando suas estratégias de planejamento de produção e seus ERP. Se por um lado a baixa acurácia nas previsões causa um problema na aplicação de estratégias empurradas de planejamento, pois requer um alto estoque de segurança associado, por outro a concentração de embarque dificulta a adoção de uma estratégia puramente puxada, já que o sistema não tem a estabilidade necessária. Para cumprir com este objetivo seis estudos de caso foram conduzidos e os resultados encontrados, suportados pela teoria, sugerem o aparecimento de um modelo híbrido eficaz para planejamento no ambiente estudado assim como o aparecimento de um sistema DSS (Decision Support System). Outra contribuição desta pesquisa foi identificar, em um dos casos, uma empresa que conseguiu atacar de maneira eficaz o fenômeno em sua causa raiz neutralizando assim seus efeitos. / The highly competitive environment of modern times has put pressure on the decision-making process in the corporate world. The trade-offs of competitive priorities such as cost, quality, service and flexibility are no longer enough. These trade-offs, albeit important in the short term, must be matched so that companies that have the best balance between them should have superior results. One of the tradeoffs widely discussed is the balance between service level and inventory. The perception is that excellence is not likely to be achieved in service without having a significant level of inventory. From this scenario comes the paradox of using MRP systems (Material Requirement Planning) versus JIT systems (Just in Time), or rather \"pushed\" systems versus \"pulled\" systems since the option for one or the other system has a close connection with inventory management. On the one hand, MRP systems are widely used in industry through ERP software; on the other hand, JIT systems have obtained better results. While many companies consider adopting one or another system, some of them adopt a hybrid process with the goal of taking the best of each system and generate superior performance. The purpose of this research is to investigate how companies inserted in markets characterized by sales peak at the end of the month (hockey-stick phenomenon), and low accuracy in demand forecasts, are applying their production planning strategies and their ERP. Low forecast accuracy causes a problem in applying pushed strategies as it requires a high safety stock associated. Conversely, the sales peak hinders the adoption of a purely pull strategy since the system does not have the necessary stability. To meet this goal, six case studies were conducted and the results found and supported by the theory suggest the emergence of an effective hybrid model for planning in the environment studied as well as the appearance of a DSS (Decision Support System). Another contribution of this research was to identify in one of the cases a company that managed to effectively tackle the phenomenon in the root cause, neutralizing its effects.