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Multidimensional approach to the supply chain
Information Control Problems in Manufacturing May 11-13, 2015. Canada Proceedigs of theOttawa, 15th IFAC Symposium on Proceedigs of the 15th IFAC Symposium on Available online at www.sciencedirect.com Information Control Problems in Manufacturing Information Control Problems in Manufacturing May 11-13, 2015. Ottawa, Canada May 11-13, 2015. Ottawa, Canada
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Multidimensional approach to the supply chain IFAC-PapersOnLine 48-3 (2015) 2121–2126 Multidimensional approach chain P. Hoffa* M. Jasiulewicz-Kaczmarek** Pawlewski*** Multidimensional approach to to the theP.supply supply chain P. P. P. Hoffa* Hoffa* M. M. Jasiulewicz-Kaczmarek** Jasiulewicz-Kaczmarek** P. Pawlewski*** Pawlewski*** *Dep. of Engineering Management, Poznan Poznań, Poland (e-mail: [email protected]). *Dep. of Engineering **Dep. ofEngineering EngineeringManagement, Management,Poznan Poznan *Dep. of Management, Poznan Poznań, Poland (e-mail: [email protected]). Poznań, Poland (e-mail: [email protected]). Poznań, Poland (e-mail: [email protected]). **Dep. ***Dep. ofEngineering EngineeringManagement, Management,Poznan Poznan **Dep. of of Engineering Management, Poznan Poznań, Poland (e-mail: [email protected]). Poznań, Poland (e-mail: [email protected]). Poznań, Poland (e-mail: [email protected]). ***Dep. ***Dep. of of Engineering Engineering Management, Management, Poznan Poznan Poznań, Poland (e-mail: [email protected]). Poland (e-mail: [email protected]). Abstract: In this article Poznań, authors propose a multidimensional approach to the supply chain. By considering processes at different levels (on a global and individual scale), analyze particular activities and the Abstract: this authors propose aa multidimensional approach the By considering relationship them is possible. focus on analyzing the to supply chain chain. in a few – using Abstract: In In between this article article authors proposeAuthors multidimensional approach to the supply supply chain. Byways considering processes at different levels (on a global and individual scale), analyze particular activities and the multidimensional They attemptand to answer the following questions: How does an individual processes at differentapproach. levels (on a global individual scale), analyze particular activities and the the relationship between possible. Authors focus activity in the supply them chainis a particular relationship between them isaffect possible. Authorsactivity? focus on on analyzing analyzing the the supply supply chain chain in in aa few few ways ways – – using using the multidimensional approach. They attempt answer following the multidimensional approach. They attempt to tomultimodal answer the theapproach following questions: questions: How How does does an an individual individual Keywords: supply chain, transport, simulation, © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. activity in the supply chain affect a particular activity? activity in the supply chain affect a particular activity? Keywords: approach Keywords: supply supply chain, chain, transport, transport, simulation, simulation, multimodal multimodal issueapproach of the executed processes in the supply chain. By 1. INTRODUCTION considering processes at different levels (on a global and executed processes in chain. By individual activities This article presents1.aINTRODUCTION multidimensional approach to supply issue issue of of the the scale), executedanalyze processesparticular in the the supply supply chain. and By 1. INTRODUCTION considering processes at different levels (on a global and between them is possible. chain. The precise analysis of processes is possible by looking relationships considering processes at different levels (on a global and individual scale), analyze activities and This aa multidimensional approach to supply at thearticle supplypresents chain from different viewpoint, firstly by scale), analyze particular particular activities and This article presents multidimensional approach to general supply individual Authors describe the multidimensional approach to the supply relationships between them is possible. chain. The precise analysis of processes is possible by looking (transport a global scale) and then isinpossible detail (individual between them is possible. chain. The on precise analysis of processes by looking relationships chain due to the size of the management. We can distinguish at the chain different viewpoint, firstly general means of transport) (fig.1). Besides, thanks to this by approach, at the supply supply chain from from different viewpoint, firstly by general tree Authors describe the multidimensional approach to level: strategic, and operational. Table shows describe the tactical multidimensional approach to the the1 supply supply (transport on global scale) and in (individual we can observe analyze between each elements Authors (transport on aa and global scale)relations and then then in detail detail (individual chain due to the size of the management. We can distinguish these levels with a description of the area We belongs to each of chain due to the size of the management. can distinguish means of transport) (fig.1). Besides, thanks to this approach, of a supply chain, including the relationship between next tree level: strategic, tactical and operational. Table 1 shows means of transport) (fig.1). Besides, thanks to this approach, theselevel: dimensions. tree strategic, tactical and operational. Table 1 shows we can observe and analyze relations between each elements levels. In the article the supply chain is presented from three we can observe and analyze relations between each elements these levels with a description of the area belongs to each of these levels with a description of the area belongs to each of of a supply chain, including the relationship between next perspectives: traditional flow), between multimodal of a supply chain, including(one-way the relationship next these Table.dimensions. 1. Level of management in supply chain. Source: own these dimensions. levels. In the article the supply chain is presented from three (presentation of an the individual transport process from usingthree the levels. In the article supply chain is presented study based on (Schmidt & Wilhelm,2010). perspectives: traditional flow), multimodal 4-level approach) and in terms(one-way of meso (showing Table. 1. Level perspectives: traditional (one-way flow), a relationship multimodal Table. 1. Level of of management management in in supply supply chain. chain. Source: Source: own own (presentation of individual transport between a transport and management). study based on (Schmidt & Wilhelm,2010). (presentation of an anlayer individual transport process process using using the the Level of study based on (Schmidt & Wilhelm,2010). 4-level Describe of level 4-level approach) approach) and and in in terms terms of of meso meso (showing (showing aa relationship relationship management between a transport layer and management). between a transport layer and management). Level Level of of Describe Describe of of level level management management - the design a logistics network in Strategic accordance to company's vision and the -main design - the thegoal; design aa logistics logistics network network in in Strategic accordance to company's vision Strategic accordance to company's vision and and the the main goal; -main describing the material flow and goal; management aspects directly related to the -implementation material flow and of material it takes - describing describing the the materialflow; flow and Tactical management aspects directly related to the into account the level directly of production management aspects related(iftoarea the implementation of material flow; it takes of the supply of chain also flow; includes this implementation material it takes Tactical Tactical into aspect); into account account the the level level of of production production (if (if area area of the supply chain also includes of the supply chain also includes this this aspect); -aspect); describe schedule of operations, analyze single activities, the goal is to make the Operational - describe schedule of operations, analyze goods in-time andof delivery to - describe schedule operations,them analyze single customers; single activities, activities, the the goal goal is is to to make make the the Operational Operational goods in-time and delivery them to goods in-time and delivery them to customers; customers; Fig. 1. Multidimensional approach of the supply chain. The Research Highlights of the performed works are follows: the multidimensional look at the supply chain on a Fig. 1. of In this authors presentapproach a new approach to thechain. analysis present Fig.article 1. Multidimensional Multidimensional approach of the the supply supply chain. The Research Highlights of the performed works follows: global and scale; the gap in theare traditional The Research Highlights of and the show performed works are follows: of processes in the supply chain, which is different from the present theindividual multidimensional look at the supply chain on (one-way) to other presented approaches. In this article authors present a new approach to the analysis present the multidimensional look at the supply chain on aa traditional one. They present proposea multidimensional lookanalysis at the global and individual scale; and show the gap in the traditional In this article authors new approach to the of and individual scale; and show the gap in the traditional of processes processes in in the the supply supply chain, chain, which which is is different different from from the the global (one-way) to traditional one. They propose multidimensional look at the (one-way) to other other presented presented approaches. approaches. Copyright 2015 IFAC traditional© one. They propose multidimensional look at the2195 2405-8963 © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. Peer review©under of International Federation of Automatic Copyright 2015 responsibility IFAC 2195Control. Copyright © 2015 IFAC 2195 10.1016/j.ifacol.2015.06.402
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The article consists of five parts. Section 2 presents the traditional approach to the supply chain – one way flow. Part 3 presents multimodal approach to the processes analysis in the whole supply chain. This approach is based on analyzing processes at four levels: business, multimodal and local processes and sources, which are needed to make these processes. Section 4 presents the supply chain in two aspects – the level of management and the level of transport. These levels are closely interrelated and interdependent. The article ends with conclusions and plans for further work.
Analyzing definitions of supply chain (in a traditional sense), it can be seen that most of them present a supply chain from operational and tactical border of dimension. At figure 2, a horizontal line shows the location of supply chain in traditional meanings.
2. TRADITIONAL APPROACH TO SUPPLY CHAIN (ONE WAY FLOW) The issue of supply chain is very complex (Sitek & Wikarek 2013, Wieland & Wallenburg 2011). In literature many different definitions of supply chain can be find. They differ because of the scope of the included operations, as well as due to the level of the describing of the chain (whether from the point of view of operational-tactical, or the wider point strategic). Different definitions of supply chain with defined dimensions are presented in table 2.
Fig. 2. Location of traditional supply chain in terms of three dimensions (strategic, tactical, operational). Source: Own study based on http://www.ecopetrol.com.co The typical structure of the supply chain is presented in figure 3. It includes the material flow from suppliers to end customers, taking into account other participating entities.
Table. 2. Definitions of supply chain.
Supplier
Warehouse
Retailer
Customer
Manufacturer
Author
Definition
Dimension
A supply chain is a global network consisting of suppliers, manufacturers, warehouses, distribution centers and retailers through which raw materials are acquired, transformed and delivered to customers.
tactical/ operational
tactical/ operational
Chang & Makatsoris (2001)
A supply chain consists of many participants – from suppliers who provide raw materials for manufacturing companies, through distribution centers and retailers, from which customers purchase the finished product. Depending on the sector, a supply chain structure can be different.
tactical/ operational/ strategic
Umeda (2013)
A supply chain system is a chain of processes from the initial raw materials to the ultimate consumption of the finished product spanning across multiple suppliercustomer links. It provides functions within and outside a company that enable the value chain to make products and provide services to the customers
Fung Chen (2004)
&
Supplier
Retailer
Manufacturer Supplier
Customer
Warehouse
Warehouse
Customer
Fig. 3. A typical supply chain. Source: (Chang & Makatsoris 2001). 3. MULTIMODAL APPROACH TO THE SUPPLY CHAIN (4-LEVEL APPROACH) Supply chain can consist of many entities, as we presented at a figure 3. From this case (and due to other) the management of supply chain can be very difficult task. We should be aware of the fact that every action, even the elementary one, affects the whole process realized in the supply chain (for example, the lack of worker for loading a car, leads to a delay in loading process, and it prolongs the entire transportation process in supply). Due to the complexity of the processes which take place within each supply chain, authors propose analyzing activities in a process way. For this purpose, the multimodal approach will be used (Pawlewski 2013). As a part of this approach, for every main process, four levels of analysis processes are highlighted: Level 3 – business process – defining the main process, the business process for the analyzed range, e.g. transport of goods from one producer to three final customers; the aim of this is a profit. Level 2 – Level of multimodal process – defining the multimodal processes, which make up the main business process. Multimodal processes are defined as processes executed along the routes consisting of parts of the routes of local processes (Pawlewski 2013, Bocewicz et al. 2012). According to this definition, multimodal processes are processes consisting of local processes.
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Level 1 – level of cyclic processes – these processes are carried out repetitively at a given point, e.g. at the point of loading, a forklift during loading a vehicle makes repetitive movements (it moves in a loop between the place of temporary storage and the load ramp). The realization directory of local processes determines the implementation of multimodal processes.
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Figure 5 presents this analysis of the supply chain.
Level 0 – The set of resources – it is the level of resources, which are necessary for the implementation of the analyzed processes (local, multimodal and then business processes). In order to make this method of analyzing the supply chain more understandable, the example of the chain consisting of one load point, one reload point and three unload points will be presented (fig.4).
Fig. 4. Scheme of analysed supply chain. When analyzing the chosen supply chain in accordance with the present multimodal approach (fig.4), we can distinguish three multimodal processes: 1) Transport of material from the load point, by reload point, to the unload point no 1 (PM1), 2) Transport of material from the load point, by reload point, to the unload point no 2 (PM2), 3) Transport of material from the load point, by reload point, to the unload point no 3 (PM3). Depending on the way of implementing transport in the presented supply chain, we will have to deal with different local processes. It means that it will be different PL when transport will be implemented by one means of transport, which after delivering goods to the specified point, will return to the starting point. The situation will be different when we use the same vehicle to cover selected sections of the route. In the next part of this article, authors will focus on the first of the mentioned cases. For this case, four local processes can be distinguished : 1) Transport of goods from the load point to reload point (PL1), 2) Transport of goods from the reload point to unload point no 1 (PL2),
Fig. 5. An example of a supply chain – multimodal and cyclic processes. It is important to realize that figure 5 does not show all the processes carried out within the framework of the planned supply chain. When we consider the issue of delivering goods from point A to point B, it is necessary to take into account the activities in the various points of loading, handling and unloading. For example, while analyzing the time of transport service, the time of loading and unloading at specified locations must also be taken into account. Therefore, for each points, it is crucial to present the processes that take place there and affect to the transport tasks. At the load point, we take into account processes occurring between the part of a warehouse, where goods are stored and between parts where goods are loaded onto a vehicle. In order to sending goods to a customer, it is necessary to download them from the storage, deliver to the loading ramps, and then load them into a means of transport. Transport of goods can be made by an employee with no use of equipment or with use of equipment such as a forklift. It is obvious that all these activities have an impact on the whole organized transport task, which directly affects to the time of departure from the starting point. In the analyzed situation, we can distinguish two cyclic processes (fig.6):
3) Transport of goods from the reload point to unload point no 2 (PL3), 4) Transport of goods from the reload point to unload point no 3 (PL4), 2197
1) transport of goods from the storage to the temporary storage in the loading parts of a warehouse (PC1), 2) transport of goods from the temporary storage in the loading parts of a warehouse to the trailer vehicle (PC2).
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In this way the selected supply chain is presented by the multimodal approach. By combining in one diagram different activities presented with use of cyclic and multimodal processes analysis, we get the whole analysis of a supply chain in the multimodal approach (4-level approach). Figure 9 presents a supply chain model as a multilayered model of the system behaviors of concurrent cyclic processes (Pawlewski 2013).
Fig. 6. Loading point – cyclic processes. Next points, which should be considered are unloading points. At these points, we should take into account processes occurring between the unload part (vehicle-trailer on unload ramp) and the storage area where goods are kept. These activities have influence on the departure time of a vehicle from the starting point. We can distinguish two cyclic processes (fig.7): 1) transport of goods from the vehicle trailer to the place of temporary storage in the unloading parts of a warehouse (PC1), 2) transport of goods from the place of temporary storage in the unloading parts of a warehouse to the place of storage in warehouse (PL2).
Fig. 8. Reload point – cyclic processes. Presented approach has many advantages. Firstly, a relation between activity at upon and higher levels are presented. It allows a better analysis of the processes, including the visual one, which enables a better management. Next, it is possible to map operations that do not create any added value from the standpoint of the object of the process (in this case goods delivered from a company to a customer); but they are necessary for the functioning of the whole process. Examples of such situation is: a return of a mean of transport from the reload point to the company or selected forklift moves. When we analyze the whole process, we see the top goal of every supply chain, which is the transport of goods from the producer to the end customer. Of course, presented approach has disadvantages too. One of them is the fact that we need much time to analyze process and every analyzed level.
Fig. 7. Unloading point – cyclic processes. The other point, which will be analyzed, is the reload point. Depending on the role of this point we can distinguish different patterns of action. For the purpose of the present work, authors will focus on one example of a reload point – where goods are unloaded, stored temporarily and then they are loaded into a new vehicle.
By a thorough analysis of processes at every level, it is possible to notice changes or deviations. Often, these seemingly "harmless" changes can have serious consequences for the entire company, on different levels of functioning and management of company (changes at an operational level, may have a result even at the strategic level). An example could be the occurrence of disturbances in the transport process. List of examples of interference associated with the realization of transport task is described in (Hoffa &Pawlewski, 2014).
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By analyzing processes in supply chain with using multimodal approach, it is possible to present activities in three dimension: strategic (main goal of company – level 3 in presented approach), tactical (processes at level 2) and operational (activities in level 1 and required resource – level 0). So, this approach shows all analyzed dimension in chapter 1 (fig. 10). 4. TWO-LEVEL APPROACH TO THE SUPPLY CHAIN Next presented approach consists of two levels – level of management and level of transportation (fig.11). The lower level in this approach concerns transportation, and the higher is about management. The method of coordination in the supply chain, and the time and manner of executing individual tasks determine the structure of the transport chain. Depending on that, the number of transport orders which the company will combine into one task, determines the actual structure of the supply chain. The activities at the transport level will also be determined through some decisions and arrangements undertaken at the management level (e.g. time of starting loading or required delivery date to individual points). The decisions taken at the management level are sent to entities responsible for transport. Fig. 9. Four-level approach to process analysis. Source: (Pawlewski 2013). Let's suppose that in the analyzed transport process, at the beginning, some disturbance happened. It is delay in loading, resulting from the lack of free ramp. Loading activity and a necessary resource (free ramp) belong to operational dimension (in the 4-level approach it is level 0 and 1). Thus, changes in this level (lack of free ramp) affect to the implementation of an entire transport process (which belongs to tactical level; in 4-level approach is level 2). The result of this disturbance is an extension time of the entire transport process, which may result as not realization the transport task in time frame. Which can make that company (which are responsible for transport) will have to pay financial penalty or even it can mean a termination of an agreement of further cooperation (result at the strategic level; in 4-level approach it is represented by level 3). By using this 4-level approach we can observe and analyze different relation between levels and the impact of changes in processes in one level to processes in the other level.
Fig.11. Transport and management level of supply chain. When we consider how to manage of supply chain, it is crucial to find the best ways of managing processes at different levels. Of course, one good answer does not exist. We have to choose the best way of analyzing and managing, depending on the structure and the main goal of the supply chain. Therefore, the method of analyzing these processes is very important. In this part of the article authors want to present the 2-level approach to supply chain – level of transportation and level of management. By using 2-level approach, it is possible to present activities in supply chain in two dimension: tactical (material flow and way of management) and operational (particular activities, which make up the entire transport process and required resource). Dimension for 2-level approach is presented in figure 12.
Fig.10. Area of multimodal approach in context of three dimensions (strategic, tactical, operational). Source: Own study based on http://www.ecopetrol.com.co
The advantage of the presented approach is an ability to analyze and management of transport processes occurring in the supply chain. By showing the relationship between these two levels, it is possible to observe changes occurring in one of them, and as a result of the other. Presentation processes in these two levels is easier than in the case of the approach 4level. However, it should be remember that it includes smaller dimension in analysis.
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making model), it is possible to observe, for example, how much time a company needs to make a decision about combining tasks and how much time a company needs to select the appropriate mode of transport, which in turn is connected with the costs incurred by the company.
REFERENCES
Fig.12. Area of 2-level approach in context of three dimensions (strategic, tactical, operational). Source: Own study based on http://www.ecopetrol.com.co
6. CONCLUSIONS AND FURTHER WORKS By using presented methods of analyzing the supply chain, it is possible to determine the interdependence of individual elements/processes in the supply chain. For each proposed approaches, dimensions were presented in context to strategic, tactical and operation level. It is worth to mention that the presented analysis of processes (described in section 3 and 4) can be simulated with use of simulation programs.
Fig.13. Model of coordination in supply chain in Flexsim program – screenshot .
Bocewicz, G., Nielsen, P., Banaszak, Z., Quang V.Q. (2012). Cyclic Steady State Refinement: Multimodal Processes Perspective, Advances in Production Management Systems, series: IFIP Advances in Information and Communication Technology, Bjørge J. F. et al. (Eds.), Vol. 384, Springer-Verlag, Berlin Heidelberg, pp. 18-27. Chang, Y., Makatsoris, H. (2001). Supply chain modelling using simulation, International Journal of Simulation,Vol.2 No1, pp.24-30. Fung, R.Y.K, Chen, T. (2004). A multiagent supply chain planning and coordination architecture, The International Journal of Advances Manufacturing Technology, Vol.25 Iss:7-8, pp. 811-819. Hoffa, P., Pawlewski, P. (2014) Agent Based Approach for Modeling Disturbances in Supply Chain, In Corchado, J.M., Bajo, J., and Other, (ed.), Higlights of Practical Applications of Heterogeneous Multi-Agent Systems, Communications in Computer and Information Science, pp. 144-155.Springer, Heidelberg. Pawlewski P. (2013). Multimodal Approach to Model and Design Supply Chain, Proceedings of IFAC MIM Conference, St. Petersburg. Schmidt, G., Wilhelm, W.E. (2000). Strategic, tactical and operational decisions in multi-national logistics networks: A review and discussion of modelling issues, International Journal of Production Research, Vol.38, Issue 7, pp.1501-1523 Sitek, P., Wikarek, J. (2013). A hybrid approach to supply chain modeling and optimization, Federated Conference on Computer Science and Information Systems, pp. 1223–1230. Umeda, S. (2013). Simulation analysis of supply chain systems with reverse logistics, Winter Simulation Conference, pp.3375-3384. Wieland, A., Wallenburg, C.M. (2011). Supply-ChainManagement in stürmischen Zeiten. Berlin. http://www.ecopetrol.com.co
Fig.14. Example of point in supply chain in transport layer (model made in Flexsim program) – screenshot. By creating a model, which represent different processes at management and transportation levels, a better analysis of their course is possible. In addition, it is possible to experiment with the model, in order to find a better way of connecting requests (coordination), which will provide a bigger profit for the organization. Figures 13 and 14 show examples of models (part of a model, like puzzles) that can be used to build the entire supply chain. By using this model (it is a decision2200
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Multidimensional approach to the supply chain IFAC-PapersOnLine 48-3 (2015) 2121–2126 Multidimensional approach chain P. Hoffa* M. Jasiulewicz-Kaczmarek** Pawlewski*** Multidimensional approach to to the theP.supply supply chain P. P. P. Hoffa* Hoffa* M. M. Jasiulewicz-Kaczmarek** Jasiulewicz-Kaczmarek** P. Pawlewski*** Pawlewski*** *Dep. of Engineering Management, Poznan Poznań, Poland (e-mail: [email protected]). *Dep. of Engineering **Dep. ofEngineering EngineeringManagement, Management,Poznan Poznan *Dep. of Management, Poznan Poznań, Poland (e-mail: [email protected]). Poznań, Poland (e-mail: [email protected]). Poznań, Poland (e-mail: [email protected]). **Dep. ***Dep. ofEngineering EngineeringManagement, Management,Poznan Poznan **Dep. of of Engineering Management, Poznan Poznań, Poland (e-mail: [email protected]). Poznań, Poland (e-mail: [email protected]). Poznań, Poland (e-mail: [email protected]). ***Dep. ***Dep. of of Engineering Engineering Management, Management, Poznan Poznan Poznań, Poland (e-mail: [email protected]). Poland (e-mail: [email protected]). Abstract: In this article Poznań, authors propose a multidimensional approach to the supply chain. By considering processes at different levels (on a global and individual scale), analyze particular activities and the Abstract: this authors propose aa multidimensional approach the By considering relationship them is possible. focus on analyzing the to supply chain chain. in a few – using Abstract: In In between this article article authors proposeAuthors multidimensional approach to the supply supply chain. Byways considering processes at different levels (on a global and individual scale), analyze particular activities and the multidimensional They attemptand to answer the following questions: How does an individual processes at differentapproach. levels (on a global individual scale), analyze particular activities and the the relationship between possible. Authors focus activity in the supply them chainis a particular relationship between them isaffect possible. Authorsactivity? focus on on analyzing analyzing the the supply supply chain chain in in aa few few ways ways – – using using the multidimensional approach. They attempt answer following the multidimensional approach. They attempt to tomultimodal answer the theapproach following questions: questions: How How does does an an individual individual Keywords: supply chain, transport, simulation, © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. activity in the supply chain affect a particular activity? activity in the supply chain affect a particular activity? Keywords: approach Keywords: supply supply chain, chain, transport, transport, simulation, simulation, multimodal multimodal issueapproach of the executed processes in the supply chain. By 1. INTRODUCTION considering processes at different levels (on a global and executed processes in chain. By individual activities This article presents1.aINTRODUCTION multidimensional approach to supply issue issue of of the the scale), executedanalyze processesparticular in the the supply supply chain. and By 1. INTRODUCTION considering processes at different levels (on a global and between them is possible. chain. The precise analysis of processes is possible by looking relationships considering processes at different levels (on a global and individual scale), analyze activities and This aa multidimensional approach to supply at thearticle supplypresents chain from different viewpoint, firstly by scale), analyze particular particular activities and This article presents multidimensional approach to general supply individual Authors describe the multidimensional approach to the supply relationships between them is possible. chain. The precise analysis of processes is possible by looking (transport a global scale) and then isinpossible detail (individual between them is possible. chain. The on precise analysis of processes by looking relationships chain due to the size of the management. We can distinguish at the chain different viewpoint, firstly general means of transport) (fig.1). Besides, thanks to this by approach, at the supply supply chain from from different viewpoint, firstly by general tree Authors describe the multidimensional approach to level: strategic, and operational. Table shows describe the tactical multidimensional approach to the the1 supply supply (transport on global scale) and in (individual we can observe analyze between each elements Authors (transport on aa and global scale)relations and then then in detail detail (individual chain due to the size of the management. We can distinguish these levels with a description of the area We belongs to each of chain due to the size of the management. can distinguish means of transport) (fig.1). Besides, thanks to this approach, of a supply chain, including the relationship between next tree level: strategic, tactical and operational. Table 1 shows means of transport) (fig.1). Besides, thanks to this approach, theselevel: dimensions. tree strategic, tactical and operational. Table 1 shows we can observe and analyze relations between each elements levels. In the article the supply chain is presented from three we can observe and analyze relations between each elements these levels with a description of the area belongs to each of these levels with a description of the area belongs to each of of a supply chain, including the relationship between next perspectives: traditional flow), between multimodal of a supply chain, including(one-way the relationship next these Table.dimensions. 1. Level of management in supply chain. Source: own these dimensions. levels. In the article the supply chain is presented from three (presentation of an the individual transport process from usingthree the levels. In the article supply chain is presented study based on (Schmidt & Wilhelm,2010). perspectives: traditional flow), multimodal 4-level approach) and in terms(one-way of meso (showing Table. 1. Level perspectives: traditional (one-way flow), a relationship multimodal Table. 1. Level of of management management in in supply supply chain. chain. Source: Source: own own (presentation of individual transport between a transport and management). study based on (Schmidt & Wilhelm,2010). (presentation of an anlayer individual transport process process using using the the Level of study based on (Schmidt & Wilhelm,2010). 4-level Describe of level 4-level approach) approach) and and in in terms terms of of meso meso (showing (showing aa relationship relationship management between a transport layer and management). between a transport layer and management). Level Level of of Describe Describe of of level level management management - the design a logistics network in Strategic accordance to company's vision and the -main design - the thegoal; design aa logistics logistics network network in in Strategic accordance to company's vision Strategic accordance to company's vision and and the the main goal; -main describing the material flow and goal; management aspects directly related to the -implementation material flow and of material it takes - describing describing the the materialflow; flow and Tactical management aspects directly related to the into account the level directly of production management aspects related(iftoarea the implementation of material flow; it takes of the supply of chain also flow; includes this implementation material it takes Tactical Tactical into aspect); into account account the the level level of of production production (if (if area area of the supply chain also includes of the supply chain also includes this this aspect); -aspect); describe schedule of operations, analyze single activities, the goal is to make the Operational - describe schedule of operations, analyze goods in-time andof delivery to - describe schedule operations,them analyze single customers; single activities, activities, the the goal goal is is to to make make the the Operational Operational goods in-time and delivery them to goods in-time and delivery them to customers; customers; Fig. 1. Multidimensional approach of the supply chain. The Research Highlights of the performed works are follows: the multidimensional look at the supply chain on a Fig. 1. of In this authors presentapproach a new approach to thechain. analysis present Fig.article 1. Multidimensional Multidimensional approach of the the supply supply chain. The Research Highlights of the performed works follows: global and scale; the gap in theare traditional The Research Highlights of and the show performed works are follows: of processes in the supply chain, which is different from the present theindividual multidimensional look at the supply chain on (one-way) to other presented approaches. In this article authors present a new approach to the analysis present the multidimensional look at the supply chain on aa traditional one. They present proposea multidimensional lookanalysis at the global and individual scale; and show the gap in the traditional In this article authors new approach to the of and individual scale; and show the gap in the traditional of processes processes in in the the supply supply chain, chain, which which is is different different from from the the global (one-way) to traditional one. They propose multidimensional look at the (one-way) to other other presented presented approaches. approaches. Copyright 2015 IFAC traditional© one. They propose multidimensional look at the2195 2405-8963 © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. Peer review©under of International Federation of Automatic Copyright 2015 responsibility IFAC 2195Control. Copyright © 2015 IFAC 2195 10.1016/j.ifacol.2015.06.402
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The article consists of five parts. Section 2 presents the traditional approach to the supply chain – one way flow. Part 3 presents multimodal approach to the processes analysis in the whole supply chain. This approach is based on analyzing processes at four levels: business, multimodal and local processes and sources, which are needed to make these processes. Section 4 presents the supply chain in two aspects – the level of management and the level of transport. These levels are closely interrelated and interdependent. The article ends with conclusions and plans for further work.
Analyzing definitions of supply chain (in a traditional sense), it can be seen that most of them present a supply chain from operational and tactical border of dimension. At figure 2, a horizontal line shows the location of supply chain in traditional meanings.
2. TRADITIONAL APPROACH TO SUPPLY CHAIN (ONE WAY FLOW) The issue of supply chain is very complex (Sitek & Wikarek 2013, Wieland & Wallenburg 2011). In literature many different definitions of supply chain can be find. They differ because of the scope of the included operations, as well as due to the level of the describing of the chain (whether from the point of view of operational-tactical, or the wider point strategic). Different definitions of supply chain with defined dimensions are presented in table 2.
Fig. 2. Location of traditional supply chain in terms of three dimensions (strategic, tactical, operational). Source: Own study based on http://www.ecopetrol.com.co The typical structure of the supply chain is presented in figure 3. It includes the material flow from suppliers to end customers, taking into account other participating entities.
Table. 2. Definitions of supply chain.
Supplier
Warehouse
Retailer
Customer
Manufacturer
Author
Definition
Dimension
A supply chain is a global network consisting of suppliers, manufacturers, warehouses, distribution centers and retailers through which raw materials are acquired, transformed and delivered to customers.
tactical/ operational
tactical/ operational
Chang & Makatsoris (2001)
A supply chain consists of many participants – from suppliers who provide raw materials for manufacturing companies, through distribution centers and retailers, from which customers purchase the finished product. Depending on the sector, a supply chain structure can be different.
tactical/ operational/ strategic
Umeda (2013)
A supply chain system is a chain of processes from the initial raw materials to the ultimate consumption of the finished product spanning across multiple suppliercustomer links. It provides functions within and outside a company that enable the value chain to make products and provide services to the customers
Fung Chen (2004)
&
Supplier
Retailer
Manufacturer Supplier
Customer
Warehouse
Warehouse
Customer
Fig. 3. A typical supply chain. Source: (Chang & Makatsoris 2001). 3. MULTIMODAL APPROACH TO THE SUPPLY CHAIN (4-LEVEL APPROACH) Supply chain can consist of many entities, as we presented at a figure 3. From this case (and due to other) the management of supply chain can be very difficult task. We should be aware of the fact that every action, even the elementary one, affects the whole process realized in the supply chain (for example, the lack of worker for loading a car, leads to a delay in loading process, and it prolongs the entire transportation process in supply). Due to the complexity of the processes which take place within each supply chain, authors propose analyzing activities in a process way. For this purpose, the multimodal approach will be used (Pawlewski 2013). As a part of this approach, for every main process, four levels of analysis processes are highlighted: Level 3 – business process – defining the main process, the business process for the analyzed range, e.g. transport of goods from one producer to three final customers; the aim of this is a profit. Level 2 – Level of multimodal process – defining the multimodal processes, which make up the main business process. Multimodal processes are defined as processes executed along the routes consisting of parts of the routes of local processes (Pawlewski 2013, Bocewicz et al. 2012). According to this definition, multimodal processes are processes consisting of local processes.
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Level 1 – level of cyclic processes – these processes are carried out repetitively at a given point, e.g. at the point of loading, a forklift during loading a vehicle makes repetitive movements (it moves in a loop between the place of temporary storage and the load ramp). The realization directory of local processes determines the implementation of multimodal processes.
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Figure 5 presents this analysis of the supply chain.
Level 0 – The set of resources – it is the level of resources, which are necessary for the implementation of the analyzed processes (local, multimodal and then business processes). In order to make this method of analyzing the supply chain more understandable, the example of the chain consisting of one load point, one reload point and three unload points will be presented (fig.4).
Fig. 4. Scheme of analysed supply chain. When analyzing the chosen supply chain in accordance with the present multimodal approach (fig.4), we can distinguish three multimodal processes: 1) Transport of material from the load point, by reload point, to the unload point no 1 (PM1), 2) Transport of material from the load point, by reload point, to the unload point no 2 (PM2), 3) Transport of material from the load point, by reload point, to the unload point no 3 (PM3). Depending on the way of implementing transport in the presented supply chain, we will have to deal with different local processes. It means that it will be different PL when transport will be implemented by one means of transport, which after delivering goods to the specified point, will return to the starting point. The situation will be different when we use the same vehicle to cover selected sections of the route. In the next part of this article, authors will focus on the first of the mentioned cases. For this case, four local processes can be distinguished : 1) Transport of goods from the load point to reload point (PL1), 2) Transport of goods from the reload point to unload point no 1 (PL2),
Fig. 5. An example of a supply chain – multimodal and cyclic processes. It is important to realize that figure 5 does not show all the processes carried out within the framework of the planned supply chain. When we consider the issue of delivering goods from point A to point B, it is necessary to take into account the activities in the various points of loading, handling and unloading. For example, while analyzing the time of transport service, the time of loading and unloading at specified locations must also be taken into account. Therefore, for each points, it is crucial to present the processes that take place there and affect to the transport tasks. At the load point, we take into account processes occurring between the part of a warehouse, where goods are stored and between parts where goods are loaded onto a vehicle. In order to sending goods to a customer, it is necessary to download them from the storage, deliver to the loading ramps, and then load them into a means of transport. Transport of goods can be made by an employee with no use of equipment or with use of equipment such as a forklift. It is obvious that all these activities have an impact on the whole organized transport task, which directly affects to the time of departure from the starting point. In the analyzed situation, we can distinguish two cyclic processes (fig.6):
3) Transport of goods from the reload point to unload point no 2 (PL3), 4) Transport of goods from the reload point to unload point no 3 (PL4), 2197
1) transport of goods from the storage to the temporary storage in the loading parts of a warehouse (PC1), 2) transport of goods from the temporary storage in the loading parts of a warehouse to the trailer vehicle (PC2).
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In this way the selected supply chain is presented by the multimodal approach. By combining in one diagram different activities presented with use of cyclic and multimodal processes analysis, we get the whole analysis of a supply chain in the multimodal approach (4-level approach). Figure 9 presents a supply chain model as a multilayered model of the system behaviors of concurrent cyclic processes (Pawlewski 2013).
Fig. 6. Loading point – cyclic processes. Next points, which should be considered are unloading points. At these points, we should take into account processes occurring between the unload part (vehicle-trailer on unload ramp) and the storage area where goods are kept. These activities have influence on the departure time of a vehicle from the starting point. We can distinguish two cyclic processes (fig.7): 1) transport of goods from the vehicle trailer to the place of temporary storage in the unloading parts of a warehouse (PC1), 2) transport of goods from the place of temporary storage in the unloading parts of a warehouse to the place of storage in warehouse (PL2).
Fig. 8. Reload point – cyclic processes. Presented approach has many advantages. Firstly, a relation between activity at upon and higher levels are presented. It allows a better analysis of the processes, including the visual one, which enables a better management. Next, it is possible to map operations that do not create any added value from the standpoint of the object of the process (in this case goods delivered from a company to a customer); but they are necessary for the functioning of the whole process. Examples of such situation is: a return of a mean of transport from the reload point to the company or selected forklift moves. When we analyze the whole process, we see the top goal of every supply chain, which is the transport of goods from the producer to the end customer. Of course, presented approach has disadvantages too. One of them is the fact that we need much time to analyze process and every analyzed level.
Fig. 7. Unloading point – cyclic processes. The other point, which will be analyzed, is the reload point. Depending on the role of this point we can distinguish different patterns of action. For the purpose of the present work, authors will focus on one example of a reload point – where goods are unloaded, stored temporarily and then they are loaded into a new vehicle.
By a thorough analysis of processes at every level, it is possible to notice changes or deviations. Often, these seemingly "harmless" changes can have serious consequences for the entire company, on different levels of functioning and management of company (changes at an operational level, may have a result even at the strategic level). An example could be the occurrence of disturbances in the transport process. List of examples of interference associated with the realization of transport task is described in (Hoffa &Pawlewski, 2014).
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By analyzing processes in supply chain with using multimodal approach, it is possible to present activities in three dimension: strategic (main goal of company – level 3 in presented approach), tactical (processes at level 2) and operational (activities in level 1 and required resource – level 0). So, this approach shows all analyzed dimension in chapter 1 (fig. 10). 4. TWO-LEVEL APPROACH TO THE SUPPLY CHAIN Next presented approach consists of two levels – level of management and level of transportation (fig.11). The lower level in this approach concerns transportation, and the higher is about management. The method of coordination in the supply chain, and the time and manner of executing individual tasks determine the structure of the transport chain. Depending on that, the number of transport orders which the company will combine into one task, determines the actual structure of the supply chain. The activities at the transport level will also be determined through some decisions and arrangements undertaken at the management level (e.g. time of starting loading or required delivery date to individual points). The decisions taken at the management level are sent to entities responsible for transport. Fig. 9. Four-level approach to process analysis. Source: (Pawlewski 2013). Let's suppose that in the analyzed transport process, at the beginning, some disturbance happened. It is delay in loading, resulting from the lack of free ramp. Loading activity and a necessary resource (free ramp) belong to operational dimension (in the 4-level approach it is level 0 and 1). Thus, changes in this level (lack of free ramp) affect to the implementation of an entire transport process (which belongs to tactical level; in 4-level approach is level 2). The result of this disturbance is an extension time of the entire transport process, which may result as not realization the transport task in time frame. Which can make that company (which are responsible for transport) will have to pay financial penalty or even it can mean a termination of an agreement of further cooperation (result at the strategic level; in 4-level approach it is represented by level 3). By using this 4-level approach we can observe and analyze different relation between levels and the impact of changes in processes in one level to processes in the other level.
Fig.11. Transport and management level of supply chain. When we consider how to manage of supply chain, it is crucial to find the best ways of managing processes at different levels. Of course, one good answer does not exist. We have to choose the best way of analyzing and managing, depending on the structure and the main goal of the supply chain. Therefore, the method of analyzing these processes is very important. In this part of the article authors want to present the 2-level approach to supply chain – level of transportation and level of management. By using 2-level approach, it is possible to present activities in supply chain in two dimension: tactical (material flow and way of management) and operational (particular activities, which make up the entire transport process and required resource). Dimension for 2-level approach is presented in figure 12.
Fig.10. Area of multimodal approach in context of three dimensions (strategic, tactical, operational). Source: Own study based on http://www.ecopetrol.com.co
The advantage of the presented approach is an ability to analyze and management of transport processes occurring in the supply chain. By showing the relationship between these two levels, it is possible to observe changes occurring in one of them, and as a result of the other. Presentation processes in these two levels is easier than in the case of the approach 4level. However, it should be remember that it includes smaller dimension in analysis.
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making model), it is possible to observe, for example, how much time a company needs to make a decision about combining tasks and how much time a company needs to select the appropriate mode of transport, which in turn is connected with the costs incurred by the company.
REFERENCES
Fig.12. Area of 2-level approach in context of three dimensions (strategic, tactical, operational). Source: Own study based on http://www.ecopetrol.com.co
6. CONCLUSIONS AND FURTHER WORKS By using presented methods of analyzing the supply chain, it is possible to determine the interdependence of individual elements/processes in the supply chain. For each proposed approaches, dimensions were presented in context to strategic, tactical and operation level. It is worth to mention that the presented analysis of processes (described in section 3 and 4) can be simulated with use of simulation programs.
Fig.13. Model of coordination in supply chain in Flexsim program – screenshot .
Bocewicz, G., Nielsen, P., Banaszak, Z., Quang V.Q. (2012). Cyclic Steady State Refinement: Multimodal Processes Perspective, Advances in Production Management Systems, series: IFIP Advances in Information and Communication Technology, Bjørge J. F. et al. (Eds.), Vol. 384, Springer-Verlag, Berlin Heidelberg, pp. 18-27. Chang, Y., Makatsoris, H. (2001). Supply chain modelling using simulation, International Journal of Simulation,Vol.2 No1, pp.24-30. Fung, R.Y.K, Chen, T. (2004). A multiagent supply chain planning and coordination architecture, The International Journal of Advances Manufacturing Technology, Vol.25 Iss:7-8, pp. 811-819. Hoffa, P., Pawlewski, P. (2014) Agent Based Approach for Modeling Disturbances in Supply Chain, In Corchado, J.M., Bajo, J., and Other, (ed.), Higlights of Practical Applications of Heterogeneous Multi-Agent Systems, Communications in Computer and Information Science, pp. 144-155.Springer, Heidelberg. Pawlewski P. (2013). Multimodal Approach to Model and Design Supply Chain, Proceedings of IFAC MIM Conference, St. Petersburg. Schmidt, G., Wilhelm, W.E. (2000). Strategic, tactical and operational decisions in multi-national logistics networks: A review and discussion of modelling issues, International Journal of Production Research, Vol.38, Issue 7, pp.1501-1523 Sitek, P., Wikarek, J. (2013). A hybrid approach to supply chain modeling and optimization, Federated Conference on Computer Science and Information Systems, pp. 1223–1230. Umeda, S. (2013). Simulation analysis of supply chain systems with reverse logistics, Winter Simulation Conference, pp.3375-3384. Wieland, A., Wallenburg, C.M. (2011). Supply-ChainManagement in stürmischen Zeiten. Berlin. http://www.ecopetrol.com.co
Fig.14. Example of point in supply chain in transport layer (model made in Flexsim program) – screenshot. By creating a model, which represent different processes at management and transportation levels, a better analysis of their course is possible. In addition, it is possible to experiment with the model, in order to find a better way of connecting requests (coordination), which will provide a bigger profit for the organization. Figures 13 and 14 show examples of models (part of a model, like puzzles) that can be used to build the entire supply chain. By using this model (it is a decision2200