Optimization of a dynamic supply portfolio considering risks and discount’s constraints

Purpose: Nowadays finding reliable suppliers in the global supply chains has become so important for success, because reliable suppliers would lead to a reliable supply and besides that orders of customer are met effectively . Yet, there is little empirical evidence to support this view, hence the purpose of this paper is to fill this need by considering risk in order to find the optimum supply portfolio. Design/methodology/approach: This paper proposes a multi objective model for the supplier selection portfolio problem that uses conditional value at risk (CVaR) criteria to control the risks of delayed, disrupted and defected supplies via scenario analysis. Also we consider discount’s constraints which are common assumptions in supplier selection problems. The proposed approach is capable of determining the optimal supply portfolio by calculating value-at-risk and minimizing conditional value-at-risk. In this study the Reservation Level driven Tchebycheff Procedure (RLTP) which is one of the reference point methods, is used to solve small size of our model through coding in GAMS. As our model is NP-hard; a meta-heuristic approach, Non-dominated Sorting Genetic Algorithm (NSGA) which is one of the most efficient methods for optimizing multi objective models, is applied to solve large scales of our model. Findings and Originality/value: In order to find a dynamic supply portfolio, we developed a Mixed Integer Linear Programming (MILP) model which contains two objectives. One objective minimizes the cost and the other minimizes the risks of delayed, disrupted and defected supplies. CVaR is used as the risk controlling method which emphases on low-probability, high-consequence events. Discount option as a common offer from suppliers is also implanted in the proposed model. Our findings show that the proposed model can help in optimization of a dynamic supplier selection portfolio with controlling the corresponding risks for large scales of real word problems. Practical implications: To approve the capability of our model various numerical examples are made and non-dominated solutions are generated. Sensitive analysis is made for determination of the most important factors. The results shows that how a dynamic supply portfolio would disperse the allocation of orders among the suppliers combined with the allocation of orders among the planning periods, in order to hedge against the risks of delayed, disrupted and defected supplies. Originality/value: This paper provides a novel multi objective model for supplier selection portfolio problem that is capable of controlling delayed, disrupted and defected supplies via scenario analysis. Also discounts, as an option offered from suppliers, are embedded in the model. Due to the large size of the real problems in the field of supplier selection portfolio a meta-heuristic method, NSGA II, is presented for solving the multi objective model. The chromosome represented for the proposed solving methodology is unique and is another contribution of this paper which showed to be adaptive with the essence of supplier selection portfolio problemPeer Reviewe

Applying total cost of ownership for strategic procurement : three industrial case studies.

In this paper we elaborate on a Total Cost of Ownership supplier selection methodology that we have constructed using three real life case studies which are presented in this article. Analysing the value chain of the firm, data on the costs generated by the purchasing policy and on supplier performance are collected using Activity Based Costing (ABC). Since a spreadsheet cannot encompass all these costs, let alone optimise the supplier selection and inventory management policy, a mathematical programming model is used. Possible savings of between 6 and 14% are obtained for the three cases.Case studies; Studies;

Supplier selection under disaster uncertainty with joint procurement

Master of ScienceDepartment of Industrial & Manufacturing Systems EngineeringJessica L. Heier StammHealth care organizations must have enough supplies and equipment on hand to adequately respond to events such as terrorist attacks, infectious disease outbreaks, and natural disasters. This is achieved through a robust supply chain system. Nationwide, states are assessing their current supply chains to identify gaps that may present issues during disaster preparedness and response. During an assessment of the Kansas health care supply chain, a number of vulnerabilities were identified, one of which being supplier consolidation. Through mergers and acquisitions, the number of suppliers within the health care field has been decreasing over the years. This can pose problems during disaster response when there is a surge in demand and multiple organizations are relying on the same suppliers to provide equipment and supplies. This thesis explores the potential for joint procurement agreements to encourage supplier diversity by splitting purchasing among multiple suppliers. In joint procurement, two or more customers combine their purchases into one large order so that they can receive quantity discounts from a supplier. This research makes three important contributions to supplier selection under disaster uncertainty. The first of these is the development of a scenario-based supplier selection model under uncertainty with joint procurement. This optimization model can be used to observe customer purchasing decisions in various scenarios while considering the probability of disaster occurrence. Second, the model is applied to a set of experiments to analyze the results when supplier diversity is increased and when joint procurement is introduced. This leads to the third and final contribution: a set of recommendations for health care organization decision makers regarding ways to increase supplier diversity and decrease the risk of disruption associated with disaster occurrence

Optimizing strategic sourcing in the healthcare supply chain with consideration of physician preference and vendor scorecards

This research focuses on the design of a procurement model for expensive medical supplies in a healthcare supply chain. A deterministic optimization model generates recommendations for optimal purchases of products in a given planning period. The model combines common concepts of supply chain procurement such as leveraging tiered pricing, ensuring supply base diversity with phenomena unique to healthcare supply chain such as consideration of physician preference for products. The deterministic optimization model minimizes total spend over a chosen planning period with consideration of four key decision parameters: Physician preference requirements (which are imposed as rules on product substitutability), Upper limits on vendor market share to ensure a suitably diverse supply base Vendors’ performance scores to impose standards for product pricing, quality, service, etc. Quantity discount rebate parameters for bulk purchasing to help contain medical costs The optimization model reveals the extent to which higher product substitutability and lower supply base diversity may help hospitals reduce total procurement costs. Experiments with the optimization model also reveal the potential consequences of rater biases in vendor scorecards on procurement cost. The various parameter combinations listed above may be used in negotiating contracts for better pricing. In summary, this research addresses questions pertinent to healthcare supply chains concerning the possible cost of physician preference for products, the impact of subjective scorecards on procurement costs, the effect of planning period on procurement plans, and the cost of vendor diversity

Comparing third party financing of litigation versus legal expenses insurance

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The impact of labels on the competitiveness of the European food label supply chain

The report studies the impact of private labels on the competitiveness of the European food processing industry and investigates whether a system of producer indication may improve the functioning of the food supply chain. The impact is studied using economic theory and empirical and legal analysis. The study is completed with an impact assessment

Empirical analysis of buyer power

This paper provides a comprehensive econometric framework for the empirical analysis of buyer power. It encompasses the two main features of pricing schemes in business-to-business relationships: nonlinear price schedules and bargaining over rents. Disentangling them is critical to the empirical identification of buyer power. Testable predictions from the theoretical analysis are delineated, and a pragmatic empirical methodology is presented. It is readily implementable on the basis of transaction data, routinely collected by antitrust authorities. The empirical framework is illustrated using data from the UK brick industry. The paper emphasizes the importance of controlling for endogeneity of volumes and for heterogeneity across buyers and sellers.

Key factors required by purchasing and supply departments in the automotive manufacturing industry

The main research problem addressed in this study was to determine the key factors required by purchasing and supply departments in the automotive manufacturing industry to be efficient and effective. To achieve this objective, it was necessary to identify five sub-objectives which were, firstly, to determine the extent to which the purchasing and supply departments in the automotive industry believe that certain key factors in pricing, quality and supplier management are required to achieve excellence. Secondly, to identify if the purchasing and supply departments in the automotive industry actually implement the key factors on pricing, quality and supplier management in practice. Thirdly, to determine if there are any additional factors other than these key factors that business firms regard as key factors to be classified as worldclass purchasing and supply departments. Fourthly, to analyse why purchasing and supply departments in the automotive manufacturing industry do not always implement these key factors. Lastly, to identify any other factors that could have a significant negative impact on the performance of purchasing and supply departments. The study commenced with an analysis and review of relevant literature from various text books, journals, publications and internet sources. The literature study covered issues such as price determination, cost management, basic negotiation strategies, managing supplier quality and the supplier base, as well as a general overview of the latest developments in purchasing and supply management in business. The purpose of the literature analysis was to establish a theoretical basis for the design of the questionnaire which was used as a research instrument in this study. A survey was conducted among selected automotive assemblers and their first and second tier manufacturing suppliers in the automotive industry. The main areas of focus in the questionnaire were pricing, quality, and supplier management. As the questions in the questionnaire related to the purchasing and supply department of a business firm, a qualified and experienced buyer in the purchasing and supply department was identified in each firm to complete the questionnaire. The empirical results from the study conducted indicated that the respondents were in strong agreement with the proposed importance of the factors of pricing, quality, and supplier management required to achieve xcellence. However, the respondents also indicated that there were various obstacles which prevented the firms from implementing these key factors. Some of the obstacles mentioned were long lead times, late deliveries from suppliers, too few competitors in the market place, supplier capacity constraints and the sustainability of suppliers. Additional obstacles that the study identified were the high workload of buyers in general, incompetent staff and insufficient manpower that affected the performance of a purchasing and supply department. The buyers were not only performing buying activities, but were also involved in logistics related activities, which increased their workload and negatively affected their performance. Lack of specialised purchasing and supply chain knowledge was identified as another obstacle to achieving excellence. The empirical study highlighted some recommendations to assist purchasing and supply departments in the automotive industry to achieve excellence and become world-class departments. Examples of these recommendations are that suppliers need to be educated on how to understand their costing models and to check their own sustainability; local purchasing and supply departments require training in the purchasing skills such as incoterms, delivery times, minimum and maximum order quantity; as well as the payment terms. Buyers should be trained to become experts in their products and packaging, as well as the manufacturing process of the product they are purchasing The business firm should only employ qualified buyers who have financial and administrative skills, as well as the ability to adapt to change and work in teams. Buyers also need to master the in-house systems and work procedures involved in purchasing a product. The empirical study also identified that the majority of buyers in the automotive manufacturing industry are senior buyers, male in gender and between the ages of 40-49. The implementation of the recommendations based on the study’s empirical findings will assist in improved pricing, quality and supply management in the automotive manufacturing industry