İMALAT İSÇİLERİNİN SEÇİM KRİTERLERİNİN BULANIK AHS YÖNTEMİ İLE ANALİZİ

An analytical way to reach the best decision is more preferable in many business platforms. When variables are quantitative and number of criteria is not high, then one can use several analysis tools and make his/her decision and solve the problem. However, many times beside the measurable variables, there exist qualitative variables for decision making problems, or people are supposed to prefer the best among the many choices. Even if only linguistic evaluations may be available for such problems, an analytical way to find the solution systematically to make a successful decision is needed. Fuzzy Analytical Hierarchy Process (Fuzzy AHP) is one of the best ways for deciding among the complex criteria structure in different levels. Fuzzy AHP is a synthetic extension of classical AHP method when the fuzziness of the decision makers is considered. In this paper, the criteria set and their importance for the selection of manufacturing employee in a firm producing shoe machines are analyzed. Finally a systematic solution and decision support are provided for management. Birçok is ortamında analitik yöntemler, en iyi kararı vermek adına daha çok tercih görmektedir. Sayısal olarak ölçülebilen degiskenlerin ve kriterlerin varlıgında kullanılabilecek birçok analiz ve problem çözme teknigi bulunabilirken, kalitatif degiskenlerle seçim ya da karar verme zorunlulugu oldugunda farklı yaklasımlara gerek duyulmaktadır. Böyle bir durumda, öznel ve sözel degerlendirmeler yapma zorunlugu dogmakla birlikte, sistematik ve analitik bir yol izlemek basarılı karar vermek açısından kaçınılmazdır. Bu kosularda özellikle karar verme ortamı bulanık veriler içeriyorsa, en çok tercih edilen tekniklerden biri de Bulanık Analitik Hiyerarsi Süreci (Bulanık AHS)dir. Karmasık kriter set ve çoklu düzey yapısında seçenekler içerisinde en iyi seçimi yapma konusunda basarılı kararlar alınmasında sık kullanıma sahiptir. Bulanık AHS karar vericilerin yaptıkları yorum ve degerlendirmelerde belli bir bulanıklık oldugu düsünüldügünde ortaya çıkan ve AHS'nin bir uzantısı olarak gelistirilen sentetik bir yaklasımdır. Bu çalısmada, ayakkabı makinalar üreten bir firma için imalatta çalısacak isçilerin seçiminde hangi kriterlerin gözetildigi ve bu kriterlerin hangi agırlıklarla kararda etkili oldugu bulanık AHS yöntemi ile analiz edilmis, firma yetkilerine sistematik bir çözüm ve karar destegi saglanmıstır

Optimized production and inventory decisions for a mixed make-to-order/make-to-stock ready-made garment manufacturer

In this thesis, a production and inventory planning model for mixed make-to-order (MTO) make-to-stock (MTS) production system in garment industry. Where the dominant production is typically for the Make-to-order production and the make-to-stock production is penetrating the mainstream production (MTO) as a way of enhancing the revenues and maintaining a positive cash flow, that are often degraded due to either seasonality of demands or production planning challenges. The model considers capacity planning for the mixed environment when there are predictable fluctuating demands. Due to the nature of the clothing business, it is challenging for a garment manufacturer to cope with seasonal changes while having the best capacity utilization. The literature acknowledges production planning in the garment industry. While a little focus was for capacity planning for seasonal fluctuating demands. Mathematical programming for capacity planning in a mixed MTO and MTS garment-manufacturing environment is a viable approach that can provide effective management decisions that can help the garment industry to strive in today’s competitive pace. The proposed model considers distributing the available capacity between MTO and MTS production and the implications of the costs and revenues for different capacity distribution. Decisions made on the production amounts, inventory levels and generated revenues are attained. The model was verified and validated by applying it to a local ready- made garment factory. The results ensured the validity of the proposed model. When analysis was made to the parameters that influence the decisions, it was found that distributing the capacity between MTO and MTS with different percentages had significant impact on the revenues and costs. The model was very sensitive to the increases in the fabric price and subcontracting costs while the overall net profits were not significantly affected by the changes in the inventory holding cost. Last, this work is useful in helping garment manufacturers adapt rapidly to seasonal changes by deploying their capacity effectively in favor of their projected seasonal plans

An Investigation into Factors Affecting the Chilled Food Industry

With the advent of Industry 4.0, many new approaches towards process monitoring, benchmarking and traceability are becoming available, and these techniques have the potential to radically transform the agri-food sector. In particular, the chilled food supply chain (CFSC) contains a number of unique challenges by virtue of it being thought of as a temperature controlled supply chain. Therefore, once the key issues affecting the CFSC have been identified, algorithms can be proposed, which would allow realistic thresholds to be established for managing these problems on the micro, meso and macro scales. Hence, a study is required into factors affecting the CFSC within the scope of Industry 4.0. The study itself has been broken down into four main topics: identifying the key issues within the CFSC; implementing a philosophy of continuous improvement within the CFSC; identifying uncertainty within the CFSC; improving and measuring the performance of the supply chain. However, as a consequence of this study two further topics were added: a discussion of some of the issues surrounding information sharing between retailers and suppliers; some of the wider issues affecting food losses and wastage (FLW) on the micro, meso and macro scales. A hybrid algorithm is developed, which incorporates the analytic hierarchical process (AHP) for qualitative issues and data envelopment analysis (DEA) for quantitative issues. The hybrid algorithm itself is a development of the internal auditing algorithm proposed by Sueyoshi et al (2009), which in turn was developed following corporate scandals such as Tyco, Enron, and WorldCom, which have led to a decline in public trust. However, the advantage of the proposed solution is that all of the key issues within the CFSC identified can be managed from a single computer terminal, whilst the risk of food contamination such as the 2013 horsemeat scandal can be avoided via improved traceability

Construcción de algoritmo aplicando relajación lagrangeana para la obtención de un límite inferior para el problema de lotificación en sistemas multinivel en entornos de coproducción y listas de materiales alternativas /

En este trabajo se presenta un algoritmo para obtener una cota inferior para el problema de lotificación en sistemas multinivel en entornos de coproducción y listas de materiales alternativas basado en Relajación Lagrangeana. El problema estudiado es un problema de programación entera mixta el cual es semejante a la optimización de un MRP con listas de materiales alternativas, con múltiples recursos en entornos de coproducción y múltiples periodos de tiempo considerando restricciones de lead time y capacidad de producción y cae dentro de la categoría NP-HARD. Para la obtención de los multiplicadores de lagrange, que penalizan la función de objetivo, se utilizó el algoritmo de optimización del subgradiente. La implementación se realizó en el IDE de desarrollo GAMS. La calibración de los parámetros del algoritmo se realizó utilizando la metodología de superficie de respuesta. La validación del algoritmo propuesto se realiza por medio de un análisis comparativo aplicado en un caso real que trata de una empresa fabricante de partes en el sector del automóvil y un caso de demanda simulada tipo estacional y tendencia con los cinco tipos básicos de configuración de cadena de suministro o lista de materiales (BOM). Los resultados obtenidos comprueban que el algoritmo propuesto alcanza soluciones cercanas al óptimo en menor tiempo en comparación al modelo original, también denominado GMOP, resuelto bajo programación entera mixta (Branch and Bound o relajación lineal entera mixta). El desarrollo de este trabajo representa un aporte a la literatura debido a que no se encuentra aplicación de la Relajación Lagrangeana en problemas de lotificación en sistemas multinivel en entornos de coproducción y listas de materiales alternativas.Incluye referencias bibliográfica

Investigating Different Types of Variability in Food Production System

A high level of competition in the food industry, specifically in the Middle East and the UK has forced companies to improve their processes by reducing lead time, waste, and costs and increasing production efficiency. The main challenge to the achievement of the process improvement objectives is the high level of process variability. Therefore, this research investigates the different types of variability in food production system and proposes a methodology to reduce the effect variability in food production system. The variability can be caused by several factors, for instance, in biscuit production lines variability can be induced due to short breakdown and long breakdown, variable processing times, variable temperature, etc. The proposed approach addresses process time variability issues associated with both make-to-stock (MTS) and make-to-order (MTO) manufacturing environments using an iterated approach. The proposed methodology integrates process mapping, (which is a lean tool for identifying value added and non-value added activities), discrete event simulation (to mirror the real production line), Taguchi orthogonal arrays (to generate different scenarios in order to investigate the effect of variability on the simulation model), correlation analysis (to identify the highest variability factors), and the rule based system (to improve food production system performance based on identified key performance indicators (KPIs)). The research uses a biscuit production line as a case study to validate the proposed methodology. The application of the proposed approach determines that the highest effected KPI is %working. The results showed that after implementation of the rule-based system, key performance improved in high variable areas. Results analysis based on before scenario shows that %working performance indicator is highly effected by variable temperature, speed, and breakdown factors for high variable areas such as baking, cooling, aligning, and packing. Based on identified factors and high variable areas, rules are developed by applying standardisation setting (SOP, WI, PP) in high variable areas and the results shows %working improved in baking by 4.78%, in cooling by 16.06%, in aligning by 0.35%, in packing machine1 by 2.5%, in packing machine2 by 2.37%, in packaging1 by 3.35%, and in packaging2 by 3.16%. The integrated method allow quick response , control the environment without production interruption, reduce number of experiments , and reducing variability in high variable areas, which narrowed the improvement in the required areas and increased its effectiveness

Understanding and improving the manufacturing and changeover process in Saudi Arabian business - a multiple case study approach

The importance of the changeover process in the manufacturing industry is becoming widely recognised. Changeover is a complete process of changing between the manufacture of one product to manufacture of an alternative product until specified production and quality rates are reached. The initiatives to improve changeover exist in industry, as better changeover process typically contribute to improved quality performance. A high-quality and reliable changeover process can be achieved through implementation of continuous or radical improvements. This research examines the changeover process of Saudi Arabian manufacturing firms because Saudi Arabia’s government is focused on the expansion of GDP and increasing the number of export manufacturing firms. Furthermore, it is encouraging foreign manufacturing firms to invest within Saudi Arabia. These initiatives, therefore, require that Saudi manufacturing businesses develop the changeover practice in order to compete in the market and achieve the government’s objectives. Therefore, the aim of this research is to discover the current status of changeover process implementation in Saudi Arabian manufacturing businesses. To achieve this aim, the main objective of this research is to develop a conceptual model to understand and examine the effectiveness of the changeover process within Saudi Arabian manufacturing firms, facilitating identification of those activities that affect the reliability and high-quality of the process. In order to provide a comprehensive understanding of this area, this research first explores the concept of quality management and its relationship to firm performance and the performance of manufacturing changeover. An extensive body of literature was reviewed on the subject of lean manufacturing and changeover practice. A research conceptual model was identified based on this review, and focus was on providing high-quality and reliable manufacturing changeover processes during set-up in a dynamic environment. Exploratory research was conducted in sample Saudi manufacturing firms to understand the features of the changeover process within the manufacturing sector, and as a basis for modifying the proposed conceptual model. Qualitative research was employed in the study with semi-structured interviews, direct observations and documentation in order to understand the real situation such as actual daily practice and current status of changeover process in the field. The research instrument, the Changeover Effectiveness Assessment Tool (CEAT) was developed to evaluate changeover practices. A pilot study was conducted by examining the CEAT, proposed for the main research. Consequently, the conceptual model was modified and CEAT was improved in response to the pilot study findings. Case studies have been conducted within eight Saudi manufacturing businesses. These case studies assessed the implementation of manufacturing changeover practice in the lighting and medical products sectors. These two sectors were selected based on their operation strategy which was batch production as well as the fact that they fulfilled the research sampling strategy. The outcomes of the research improved the conceptual model, ultimately to facilitate the firms’ adoption and rapid implementation of a high-quality and reliability changeover during the set-up process. The main finding of this research is that Quality’s factors were considering the lowest levels comparing to the other factors which are People, Process and Infrastructure. This research contributes to enable Saudi businesses to implement the changeover process by adopting the conceptual model. In addition, the guidelines for facilitating implementation were provided in this thesis. Therefore, this research provides insight to enable the Saudi manufacturing industry to be more responsive to rapidly changing customer demands