QPR Knowledge Base 2012.1

Hierarchical Modeling

Hierarchical Modeling

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Hierarchical Modeling

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A process model can include multiple process levels, which creates hierarchy in the model. Each process level can be viewed as a separate process, which is part of the top-level process. Process levels are created using subprocesses. Creating a subprocess on one level creates a new process level under the current one. This subprocess can then be modeled in more detail in its own flow chart.

 

Same process step can be used or referenced - in several places in the model. This is especially useful for subprocesses, which are similar in several processes. This is done by instantiating the process step, see Defining Instances. Two or more subprocesses can also be combined into one single process level, see Combining Subprocesses.

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With QPR Modeling Client information can also be modeled hierarchically. A model element called information item can be part of several other model elements and can have various information items under it. This is similar to resource hierarchy introduced later in this manual.

 

Information hierarchy can be used to two modeling purposes:

 

bullet3  modeling data structures

bullet3  using compositions/decompositions of information flows on different process levels

 

The picture below shows an example of an information hierarchy. In this example an order information item is composed of two other information items: product ordered and the customer. The customer is used also as an element in the decomposition of the meeting information item.

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Information flows can be combined and split according to the existing information hierarchy or new hierarchies can be created. The following examples show how information flows can be split and combined.

 

In the picture below, one information flow carrying information item I1 exists. This flow can be split into flows carrying information items I3 and I4 in one or all of the process levels it exists in. Splitting the flow creates a new flow object (one flow can leave from a place and end at another place, carrying one information item). If the flow is split in one level, the flow is not (automatically) split in the other levels but is seen as one arrow carrying the original information item.

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At this point (shown in picture below) the model contains two flows, I3 from PS1.1 to PS2.1 and flow I4 from PS 1.2 to PS2.1. Flow I4 could be further split to flows I7 and I8 creating another new flow object. If the model contained flow I2, it could be split into flows I4, I5 and I6.

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Information flows can also be combined by the user. When flows are combined, information hierarchy is used to deduce what information item the resulting combination flow will carry. If there is no information item that is a combination of the selected flows, QPR Modeling Client will create a new parent node for the information items of the combined information flow. An example of combining flows is shown in the picture below.

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In addition to information flows it is also possible to model control flows. This flow type allows more informal flow modeling. In QPR Modeling Client information must be quite thoroughly modeled, which can be a nuisance when doing 'rough' modeling. Control flows can be used in a more informal manner to model dependencies and control flows in the process.