Intended learning outcomes: Describe MEDILS (Method for Description of Integrated Logistics Systems) and its symbols.
The order is the main instrument of logistics, and its processing is the control flow of logistics, both within and among companies. The form of the contract is unimportant: it may be a detailed written contract, or a simple card in a pull system (a Kanban).
Order processing can be compared to a freight train. The cars are coupled together, and the train moves along a certain route. As it goes, goods or information are added to the train. Stopping at certain stations, it signals to other trains to start out and supply goods or information. Before finally ending its journey, our freight train also delivers goods and information to trains traveling farther on. An observer could sit in the locomotive of the order train and observe the happenings. MEDILS (Method for Description of Integrated Logistics Systems) was designed from this observation point. MEDILS goes beyond the classical flowchart, which was introduced to better understand processes, showing flows, tasks, waiting states, storages, and so on. Figure 4.1.2.1 introduces the symbols used in MEDILS.
Fig. 4.1.2.1 MEDILS symbols.
- A double arrow represents the flow of goods. In the industrial sector, goods are usually tangible, but they can be information that go with the product from the start, such as drawings or specifications. In the service sector, goods are often intangible. In banks or insurance firms, for example, goods are often composed of information.
- A single arrow denotes the flow of data for planning & control. This is the flow of information required for administrative and planning purposes. Data describe the characteristics of goods in an appropriate way. Every goods flow is a self-description and thus is also data flow, although it is not drawn separately as such.
- A broken arrow represents the control flow. This is made up of information that deals with control of the flow of goods and data. Every goods flow and every data flow are also control flow, although they are not drawn separately as such.
- A hexagon stands for a goods store. Depending on the kind of goods, this may be a warehouse, information store, and so on. An object in this store stands for certain goods and thus represents a waiting state in the flow of goods. In principle, it may stay in this state for an indefinite length of time in the store.
- A rectangle with a double line on the left represents a data store. An object in this store stands for a certain quantity of data (for example, an order), and it is a waiting state in the flow of data. It may remain in store in this state for an indefinite period of time. The object can be described in more detail by the symbol.
- A circle stands for a process store, a kind of intermediate store in the logistics process. We can think of a process store in the flow of data or nonmaterial goods (information) as a mailbox. An object is the envelope addressed with control information, while the data are found inside the envelope. A process store in the flow of material goods can be seen as a buffer or transit camp. An object is a crate inscribed with control information, while the goods are found inside the crate.
A process store stores tasks waiting in line to be processed. The impetus for processing an object is given by an event: a sensor, such as the human eye, registers a state and finds an envelope in the mailbox. Thus, the event is an implicit part of process storage. - A rectangle represents a logistics task that may be described in detail within the rectangle. If the effect of a task is the important aspect, the rectangle stands for a function. If procedure according to plan is the focus, the rectangle stands for a method. If the focus is the way of implementation, the well-known value-adding arrow, which stands for a process, is used instead of the rectangle. A task or process can be “nuclear” or comprise subtasks or subprocesses, which are connected via flows.
- The rectangle in the shape of an arrow represents a logistics system (LS) in the direction of the temporal axis. The logistics system includes logistics tasks, states, flows, and sublogistics. It has its own order and process management, which is indicated by the doubled top line. As compared to the simple value-adding arrow, a logistics system includes not only the process itself, but also the process store containing the trigger event(s), that is, the impetus to start the process.
Continuation in next subsection (4.1.2b).
Course section 4.1: Subsections and their intended learning outcomes
4.1 Elements of Business Process Management
Intended learning outcomes: Produce an overview on terms in business process engineering. Describe order management and graphical representation of logistics processes.
4.1.1 Terms in Business Process Engineering: State and Event, Core Competeny and Core Process
Intended learning outcomes: Present concepts in business process engineering and management, state and event. Differentiate between core competencies and core processes of a company.
4.1.2 Order Management and Graphical Representation of Logistics Processes
Intended learning outcomes: Describe MEDILS (Method for Description of Integrated Logistics Systems) and its symbols.
4.1.2b Graphical Representation of Logistics Processes: Connection of the MEDILS Symbols
Intended learning outcomes: Explain the connections of the MEDILS symbols.
