# Process Modeling, Er Diagram and Logical Data Modeling

Topics: Data flow diagram, Functional flow block diagram, Entity-relationship model Pages: 5 (969 words) Published: January 5, 2011
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Process Modeling, ER diagram and Logical Data Modeling

Authors

Yogini Wagh

Process Modeling

Process modeling is the concise description of the total variation in one quantity, by partitioning it into a deterministic component given by a mathematical function of one or more other quantities, plus a random component that follows a particular probability distribution. Software process modeling and business process modeling are the techniques for obtaining a better understanding of business processes. In other terms, it is a model of one or more business processes, and defines the ways in which operations are carried out to accomplish the intended objectives of an organization. It can describe the workflow or the integration between business processes. It can be constructed in multiple levels. The term "business process modeling" itself was coined in the 1960s in the field of system engineering. Business process modeling diagrams are:

▪ Use case diagrams
▪ Activity diagrams and flow chart,
▪ functional flow block diagram,
▪  data flow diagram, control flow diagram,
▪ Gantt chart, PERT diagram, and IDEF
Some business process modeling techniques are:

▪ Business Process Modeling Notation (BPMN)
▪ Extended Business Modeling Language (xBML)
▪ Event-driven process chain (EPC)
▪ Unified Modeling Language (UML),

Process modeling has now become the base of defining and designing the workflow or the integration between business processes, which also supports data collection, data flow analysis, process flow diagrams and reporting facilities. As process can be further modularized into sub processes which can have their own attributes. The analysis of business processes typically includes the mapping of processes and sub-processes down to activity level or task level. A high level process model not only helps to channelize and control a process towards desired goal but can find out process bottlenecks and logical error which may impact a process output.BPM suite software provides programming interfaces (web services, application program interfaces (APIs)) which allows us to design process model and to optimize it by analyzing the process parameters, inputs, outputs etc to leverage the BPM engine (BRE).

DATA FLOW DIAGRAM

Data flow diagrams (DFDs) are symbolic representation of systems. Most data flow modeling methods use four kinds of symbols to represent four kind of system component.

• Processes

• Data store

• Data flows

• External entities

We can use two different types of notations on your data flow diagrams: Yourdon & Coad or Gane & Sarson.

Process Notations

A process transforms incoming data flow into outgoing data flow.

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Gane and Sarson Process Notation

Datastore Notations

Datastores are repositories of data in the system. They are sometimes also referred to as files.

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Gane and Sarson Datastore Notations

Dataflow Notations

Dataflows are pipelines through which packets of information flow. Label the arrows with the name of the data that moves through it.

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Y&C and G&S respectively

External Entity Notations

External entities are objects outside the system, with which the system communicates. External entities are sources and destinations of the system's inputs and outputs.

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Y&C and G&S respectively

Data Flow Diagram Layers

Draw data flow diagrams in several nested layers. A single process node in a context diagram can be expanded to show a more detailed high level data flow diagram. We draw the context diagram first, followed by various layers of data flow diagrams.

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Logical and Physical Data Flow Diagram

Many designers distinguish between physical and logical DFDs. The basic difference is physical functions and closer to the usage world, they...