Using the max-sum algorithm for supply chain emergence in dynamic multiunit environments

Supply chain formation (SCF) is the process of determining the set of participants and exchange relationships within a network with the goal of setting up a supply chain that meets some predefined social objective. Many proposed solutions for the SCF problem rely on centralized computation, which presents a single point of failure and can also lead to problems with scalability. Decentralized techniques that aid supply chain emergence offer a more robust and scalable approach by allowing participants to deliberate between themselves about the structure of the optimal supply chain. Current decentralized supply chain emergence mechanisms are only able to deal with simplistic scenarios in which goods are produced and traded in single units only and without taking into account production capacities or input-output ratios other than 1:1. In this paper, we demonstrate the performance of a graphical inference technique, max-sum loopy belief propagation (LBP), in a complex multiunit unit supply chain emergence scenario which models additional constraints such as production capacities and input-to-output ratios. We also provide results demonstrating the performance of LBP in dynamic environments, where the properties and composition of participants are altered as the algorithm is running. Our results suggest that max-sum LBP produces consistently strong solutions on a variety of network structures in a multiunit problem scenario, and that performance tends not to be affected by on-the-fly changes to the properties or composition of participants.

Life cycle assessment in the food supply chain:a case study

This research aims at assessing the environmental impact of the poultry supply chain from cradle to grave using case study research and also life cycle assessment (LCA). While a limited number of generic poultry production LCA studies have been published, fewer yet assess the whole process of a specific organisation, none comparing the increased impact of further processing. Our results show that irrespectively of the impact assessment method utilised, the process of producing portions is considerably higher in total environmental impact due to the extra raw material required to produce the same mass into retail. Our research contributes to the growing number of LCA studies and could be used by practitioners for comparison against national and international averages. From a theoretical point of view, this research provides new insights into the relationship between vertically integrated supply chains and environmental performance which has not been examined in the past.

The implementation of supply chain management theory in practice:an empirical investigation

Purpose: The purpose of the research described in this paper is to disentangle the rhetoric from the reality in relation to supply chain management (SCM) adoption in practice. There is significant evidence of a divergence between theory and practice in the field of SCM. Design/methodology/approach: Based on a review of extant theory, the authors posit a new definitional construct for SCM – the Four Fundamentals – and investigated four research questions (RQs) that emerged from the theoretical review. The empirical work comprised three main phases: focussed interviews, focus groups and a questionnaire survey. Each phase used the authors’ definitional construct as its basis. While the context of the paper’s empirical work is Ireland, the insights and results are generalisable to other geographical contexts. Findings: The data collected during the various stages of the empirical research supported the essence of the definitional construct and allowed it to be further developed and refined. In addition, the findings suggest that, while levels of SCM understanding are generally quite high, there is room for improvement in relation to how this understanding is translated into practice. Research limitations/implications: Expansion of the research design to incorporate case studies, grounded theory and action research has the potential to generate new SCM theory that builds on the Four Fundamentals construct, thus facilitating a deeper and richer understanding of SCM phenomena. The use of longitudinal studies would enable a barometer of progress to be developed over time. Practical implications: The authors’ definitional construct supports improvement in the cohesion of SCM practices, thereby promoting the effective implementation of supply chain strategies. A number of critical success factors and/or barriers to implementation of SCM theory in practice are identified, as are a number of practical measures that could be implemented at policy/supply chain/firm level to improve the level of effective SCM adoption. Originality/value: The authors’ robust definitional construct supports a more cohesive approach to the development of a unified theory of SCM. In addition to a profile of SCM understanding and adoption by firms in Ireland, the related critical success factors and/or inhibitors to success, as well as possible interventions, are identified.

A knowledge driven approach towards the validation of externally acquired traceability datasets in supply chain business processes

The sharing of near real-time traceability knowledge in supply chains plays a central role in coordinating business operations and is a key driver for their success. However before traceability datasets received from external partners can be integrated with datasets generated internally within an organisation, they need to be validated against information recorded for the physical goods received as well as against bespoke rules defined to ensure uniformity, consistency and completeness within the supply chain. In this paper, we present a knowledge driven framework for the runtime validation of critical constraints on incoming traceability datasets encapuslated as EPCIS event-based linked pedigrees. Our constraints are defined using SPARQL queries and SPIN rules. We present a novel validation architecture based on the integration of Apache Storm framework for real time, distributed computation with popular Semantic Web/Linked data libraries and exemplify our methodology on an abstraction of the pharmaceutical supply chain.

Detecting EPCIS exceptions in linked traceability streams across supply chain business processes

The EPCIS specification provides an event oriented mechanism to record product movement information across stakeholders in supply chain business processes. Besides enabling the sharing of event-based traceability datasets, track and trace implementations must also be equipped with the capabilities to validate integrity constraints and detect runtime exceptions without compromising the time-to-deliver schedule of the shipping and receiving parties. In this paper we present a methodology for detecting exceptions arising during the processing of EPCIS event datasets. We propose an extension to the EEM ontology for modelling EPCIS exceptions and show how runtime exceptions can be detected and reported. We exemplify and evaluate our approach on an abstraction of pharmaceutical supply chains.

Advances in decision support systems on the endeavour for supply chain optimality

Industry practitioners are seeking to create optimal logistics networks through more efficient decision-making leading to a shift of power from a centralized position to a more decentralized approach. This has led to researchers, exploring with vigor, the application of agent based modeling (ABM) in supply chains and more recently, its impact on decision-making. This paper investigates reasons for the shift to decentralized decision-making and the impact on supply chains. Effective decentralization of decision-making with ABM and hybrid modeling is investigated, observing the methods and potential of achieving optimality.

Modelling and linking transformations in EPCIS governing supply chain business processes

Supply chains comprise of complex processes spanning across multiple trading partners. The various operations involved generate large number of events that need to be integrated in order to enable internal and external traceability. Further, provenance of artifacts and agents involved in the supply chain operations is now a key traceability requirement. In this paper we propose a Semantic web/Linked data powered framework for the event based representation and analysis of supply chain activities governed by the EPCIS specification. We specifically show how a new EPCIS event type called "Transformation Event" can be semantically annotated using EEM - The EPCIS Event Model to generate linked data, that can be exploited for internal event based traceability in supply chains involving transformation of products. For integrating provenance with traceability, we propose a mapping from EEM to PROV-O. We exemplify our approach on an abstraction of the production processes that are part of the wine supply chain.

Managing supply chain knowledge in the new product development process:a social network analysis approach

The aim of this paper is to propose a conceptual framework for studying the knowledge transfer problem within the supply chain. The social network analysis (SNA) is presented as a useful tool to study knowledge networks within supply chain, to visualize knowledge flows and to identify the accumulating knowledge nodes of the networks. © 2011 IEEE.

Ellátási lánc kapcsolatok modellezése = Modeling of supply chain relationships

A dolgozatban az ellátási láncokban meglévő diadikus kapcsolatok minőségét állítjuk a vizsgálatok középpontjába. Az irodalomban számtalan megközelítés ismert az ellátási lánc kapcsolatok fejlődésének leírására. Ezen fejlődési elméletek inkább elméleti szinten írják le a diadikus kapcsolatok változását, annak empirikus tesztelhetőségét nem vizsgálják. Dolgozatunkban kísérletet teszünk az ellátási lánc kapcsolatok fejlődésének empirikus vizsgálatára. Arra próbálunk választ találni, hogy az életciklus hipotézis az üzleti kapcsolatok időbeli fejlődésére alkalmazható-e. = Our paper combines two approaches using data of an internet based questionnaire and applying quantitative analysis it tests the hypothesis business relationship development in time can be described with the concept of life cycle. The concept of life cycle is widely used in business research. Among others the diffusion of innovation is described using this concept, or the concept of product life cycle just to name a few. All of these researches analyze the life cycle along a specific variable (for example the volume of sales or revenue in case of the product life cycle) which (except the last stage of the cycle, the decline) has a cumulative character resulting in the widely known specific shape of a life cycle. Consequently testing a life cycle hypothesis inevitably means the acceptance of some type cumulativity in the development.

Cooperation in an HMMS-type supply chain: A management application of cooperative game theory = Kooperáció egy HMMS-típusú ellátási láncban: A kooperatív játékelmélet egy menedzsment alkalmazása

We apply cooperative game theory concepts to analyze a Holt-Modigliani-Muth-Simon (HMMS) supply chain. The bullwhip effect in a two-stage supply chain (supplier-manufacturer) in the framework of the HMMS-model with quadratic cost functions is considered. It is assumed that both firms minimize their relevant costs, and two cases are examined: the supplier and the manufacturer minimize their relevant costs in a decentralized and in a centralized (cooperative) way. The question of how to share the savings of the decreased bullwhip effect in the centralized (cooperative) model is answered by the weighted Shapley value, by a transferable utility cooperative game theory tool, where the weights are for the exogenously given “bargaining powers” of the participants of the supply chain. = A cikkben a kooperatív játékelmélet fogalmait alkalmazzuk egy Holt-Mogigliani-Muth-Simon-típusú ellátási lánc esetében. Az ostorcsapás-hatás elemeit egy beszállító-termelő ellátási láncban ragadjuk meg egy kvadratikus készletezési és termelési költség mellett. Feltételezzük, hogy mindkét vállalat minimalizálja a releváns költségeit. Két működési rendszert hasonlítunk össze: egy hierarchikus döntéshozatali rendszert, amikor először a termelő, majd a beszállító optimalizálja helyzetét, majd egy centralizált (kooperatív) modellt, amikor a vállalatok az együttes költségüket minimalizálják. A kérdés úgy merül fel, hogy a csökkentett ostorcsapás-hatás esetén hogyan osszák meg a részvevők ebben a transzferálható hasznosságú kooperatív játékban a költség megtakarítást, exogén módon adott tárgyalási pozíció mellett.

The analysis of bullwhip effect in a HMMS-type supply chain

The aim of the paper is to investigate the well-known bullwhip effect of supply chains. Control theoretic analysis of bullwhip effect is extensively analyzed in the literature with the Laplace transform. This paper tries to examine the effect for an extended Holt–Modigliani–Muth–Simon model. A two-stage supply chain (supplier–manufacturer) is studied with quadratic costs functional. It is assumed that both firms minimize the relevant costs. The order of the manufacturer is delayed with a known constant. Two cases are examined: supplier and manufacturer minimize the relevant costs decentralized, and a centralized decision rule. The question is answered, how to decrease the bullwhip effect.

The analysis of bullwhip effect in a HMMS-type supply chain

The aim of the paper is to investigate the well-known bullwhip effect of supply chains. Control theoretic analysis of bullwhip effect is extensively analyzed in the literature with Laplace transform. This paper tries to examine the effect for an extended Holt-Modigliani-Muth-Simon model. A two-stage supply chain (supplier-manufacturer) is studied with quadratic costs functional. It is assumed that both firms minimize the relevant costs. The order of the manufacturer is delayed with a known constant. Two cases are examined: supplier and manufacturer minimize the relevant costs decentralized, and a centralized decision rule. The question is answered, how to decrease the bullwhip effect.

A tranzakciós költségek elmélete és a társadalmi csereelmélet hatásai a bizalomra az ellátási láncban (Affects of Transaction cost and Social Exchange Constructs on trust In supply chain relationship)

A szerzők alapvető feltételezése, hogy az ellátási láncban a bizalom ösztönzi a felek közötti elkötelezettséget. Továbbá a bizalom növeli annak a lehetőségét, hogy az ellátási lánc sikeresen működjön. Ugyanakkor, a felek közötti bizalom hiánya gyakran megnöveli a tranzakciós költségeket, és így csökkenti a hatékonyságot. A cikkben bemutatott kutatás adatgyűjtésére több országban – Franciaországban, Magyarországon, Dél-Koreában, Tunéziában és az Egyesült Államokban – került sor. Összesen 729 érvényes kérdőív érkezett vissza, amelyeket a különböző ellátási láncok résztvevői töltöttek ki. A kutatási eredmények szerint az ellátási láncokon belüli üzleti kapcsolatokban a tranzakciós költségek elméletének összetevői (kapcsolatspecifikusság és viselkedési bizonytalanság), valamint a társadalmi csereelmélet tényezői (lecserélhetőség, észlelt megelégedettség, a partner hírneve és észlelt konfliktus) szoros kapcsolatban állnak a bizalom és az elkötelezettség változóival. _____ This article is based on the assumption that trust promotes commitment between partners in the supply chain and improves the chances of return on supply chain success. In contrast, a lack of trust between them often increases transaction costs and results in inefficiency. The results of this research, based on multi-country surveys with 729 returns from France, Hungary, Korea, Tunisia and the United States on supply chain professionals, reveals a strong affect of transaction cost constructs (TCC) (asset specificity and behavioral uncertainty) and social exchange constructs (SEC) (replaceability, perceived satisfaction, partner reputation, and perceived conflict) on trust-commitment variables in partnership based supply chain relationships. This paper employed a structural equation model to extract information from the survey data. Among the findings, the research indicates that a firm’s trustcommitment in dealing with their supply chain partnership is highly associated with not only transaction cost, but more so with social exchange variables. This study may open a new research avenue in that there is another construct, SEC, beside TSC that influences the degree of trust and commitment.

Supply chain position and servitization efforts of companies in Eastern and Western Europe

Our paper investigates the supply chain position of manufacturing companies in Europe, and the relation of this position to the extent and kind of services these companies provide. Our research builds on analyzing differences between Western and Eastern European companies. For the empirical research the database from the fifth round of the International Manufacturing Strategy Survey is used which covers 445 manufacturing companies from 13 European countries. Based on the connection between supply chain position and the extent and type of services offered dominant business models are identified both in Eastern and Western Europe.

Optimizing Supply Chain Performance in China with Country-Specific Supply Chain Coordination

The implementation of country-specific supply chain coordination techniques ensures an optimal global supply chain performance. This paper looks at success factors going with a supply chain coordination strategy within the global supply chain of a successful, medium-sized, privately-owned company, one having locations in North America (USA), Europe (Hungary) and Asia (China). Through the shown GSL’s Chinese plant, we will endeavor to argue that increased collaboration in the supply network with appropriate supply chain coordination brings down not only the inventory level but can also improve conformance quality and reduce quoted lead times.