Jesús Lozano

Application of distributed intelligence to reduce the bullwhip effect

The paper applies distributed intelligence to the bullwhip or Forrester effect, which it manages to reduce in a range of time series to which a genetic algorithm was applied. The paper is divided into four parts. The first provides an overview of the Forrester, or bullwhip, effect. The second describes the genetic algorithms in terms of being devices that provide the model with intelligence, and introduces the agent network and the general model that supports them. The third describes the software used in the model described. The final section provides numeric examples and draws a number of conclusions.

On macroeconomic characteristics of pharmaceutical generics and the potential for manufacturing and consumption under fuzzy conditions

OBJECTIVEnThe aim of this paper is to develop a methodology that is useful for analyzing, from a macroeconomic perspective, the aggregate demand and the aggregate supply features of the market of pharmaceutical generics. In order to determine the potential consumption and the potential production of pharmaceutical generics in different countries, two fuzzy decision support systems are proposed.nnnMETHODS AND MATERIALSnTwo fuzzy decision support systems, both based on the Mamdani model, were applied in this paper. These systems, generated by Matlab Toolbox Fuzzy (v. 2.0), are able to determine the potential of a country for the manufacturing or the consumption of pharmaceutical generics. The systems make use of three macroeconomic input variables.nnnRESULTSnIn an empirical application of our proposed methodology, the potential towards consumption and manufacturing in Holland, Sweden, Italy and Spain has been estimated from national indicators. Cross-country comparisons are made and graphical surfaces are analyzed in order to interpret the results.nnnCONCLUSIONSnThe main contribution of this work is the development of a methodology that is useful for analyzing aggregate demand and aggregate supply characteristics of pharmaceutical generics. The methodology is valid for carrying out a systematic analysis of the potential generics have at a macrolevel in different countries. The main advantages of the use of fuzzy decision support systems in the context of pharmaceutical generics are the flexibility in the construction of the system, the speed in interpreting the results offered by the inference and surface maps and the ease with which a sensitivity analysis of the potential behavior of a given country may be performed.

Determining warehouse number and location in Spain by cluster analysis

The aim of the present article is to decide the ideal number of warehouses for a food manufacturer in the north of Spain (Asturias) for the year 2000, and their ideal location in the Spanish Peninsula by cluster analysis. The stages followed are to comment first on the underlying assumptions of the study, then on the methodology and the structure of the program developed to solve the problem, as well as on their input and output files. How the cluster and cost are calculated is discussed and finally the solution to this real case is provided.

Exploring the interaction of inventory policies across the supply chain

The Bullwhip Effect, which refers to the increasing variability of orders traveling upstream the supply chain, has shown to be a severe problem for many industries. The inventory policy of the various nodes is an important contributory factor to this phenomenon, and hence it significantly impacts on their financial performance. This fact has led to a large amount of research on replenishment and forecasting methods aimed at exploring their suitability depending on a range of environmental factors, e.g. the demand pattern and the lead time. This research work approaches this issue by seeing the whole picture of the supply chain. We study the interaction between four widely used inventory models in five different contexts depending on the customer demand variability and the safety stock. We show that the concurrence of distinct inventory models in the supply chain, which is a common situation in practice, may alleviate the generation of inefficiencies derived from the Bullwhip Effect. In this sense, we demonstrate that the performance of each policy depends not only upon the external environment but also upon the position within the system and upon the decisions of the other nodes. The experiments have been carried out via an agent-based system whose agents simulate the behavior of the different supply chain actors. This technique proves to offer a powerful and risk-free approach for business exploration and transformation. We analyze different smoothing replenishment rules in the Beer Game scenario.KAOS methodology is used to devise the agent-based simulation model.The concurrence of distinct inventory models may mitigate the Bullwhip Effect.Forecasting is a more robust solution than adding a proportional controller.ABMS is a powerful approach for exploring and transforming the supply chain.

Measuring the efficiency of large pharmaceutical companies: an industry analysis

This paper evaluates the relative efficiency of a sample of 37 large pharmaceutical laboratories in the period 2008–2013 using a data envelopment analysis (DEA) approach. We describe in detail the procedure followed to select and construct relevant inputs and outputs that characterize the production and innovation activity of these pharmaceutical firms. Models are estimated with financial information from Datastream, including R&D investment, and the number of new drugs authorized by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) considering the time effect. The relative performances of these firms—taking into consideration the strategic importance of R&D—suggest that the pharmaceutical industry is a highly competitive sector given that there are many laboratories at the efficient frontier and many inefficient laboratories close to this border. Additionally, we use data from S&P Capital IQ to analyze 2071 financial transactions announced by our sample of laboratories as an alternative way to gain access to new drugs, and we link these transactions with R&D investment and DEA efficiency. We find that efficient laboratories make on average more financial transactions, and the relative size of each transaction is larger. However, pharmaceutical companies that simultaneously are more efficient and invest more internally in R&D announce smaller transactions relative to total assets.

Modeling a System of Public – Private Management of Business Areas

Currently, the management structures of the business areas and further industrial sites respond to inefficient models, regardless if is the Public or Private Sector who assumes that management. So far an ideal formula has not been found to ensure the provision of basic and advanced services. Nor is there any national solid reference of Public Private Partnership in the business areas management. Although this already exists in the Real Estate Industry, its analysis is far from the purpose of this paper. Here it is analyzed the model of the British BID (Business Improvement Districts), very successful in revitalizing urban centers and small businesses, and their possible application in the business areas of Spain. This work includes, based on critical analysis carried out on three experiences in England, the definition of a new mixed formula called Concerted Management Model, that relies on the currently existing Spanish legislation and that fully reflects the spirit of the BID system.

Agents Playing the Beer Distribution Game: Solving the Dilemma Through the Drum-Buffer-Rope Methodology

The Beer Distribution Game (BDG) is a widely used experiential learning simulation game aimed at teaching the basic concepts around Supply Chain Management (SCM). The goal in this problem is to minimize inventory costs while avoiding stock-outs –hence the players face the dilemma between storage and shortage. Human players usually get confused giving rise to significant inefficiencies in the supply chain, such as the Bullwhip Effect. This research paper shows how artificial agents are capable of playing the BDG effectively. In order to solve the dilemma, we have integrated supply chain processes (i.e. a collaborative functioning) through the Drum-Buffer-Rope (DBR) methodology. This technique, from Goldratt’s Theory of Constraints (TOC), is based on bottleneck management. In comparison to traditional alternatives, results bring evidence of the great advantages induced in the BDG by the systems thinking. Both the agent-based approach and the BDG exercise have proved to be very effective in illustrating managers the underlying structure of supply chain phenomenon.

Zoning by k-Means over a Large Data Set

In this paper, for zoning a large set of locations data we apply the k-means clustering algorithm. The results were plotted graphically and were satisfactory, so we conclude that the algorithm is useful despite the size of the data, at least for low data dimensions (latitude, longitude).

Lower bounds for estimating workforce size in a 24/7 company

A company providing services in a 24/7 basis faces the problem of determining what are the workers prerequisites per shift, and after that estimating the lower bounds of workforce size that could provide the continuous service. In this paper we solve the estimating problem according to characteristics of the contraction, vacation period and degree of absenteeism.

Management of working shifts using the constraint programming paradigm

After an introduction to constraint programming and the man power job shifting problem, we applied the constraint programming paradigm in the development of C code to make year wide calendars for a given prerequisites. We present a diagram of the program which shows a very efficient way to solve the problem. The resulting multi-shift calendars were well balanced between shifts and were produced in short computational time.