Data Flow Modeling

Data Flow Modeling and Data Flow Diagrams (DFD):

In Business Process, DFD is a top-down approach, that focuses on the flow of data between various Business Processes and helps to capture & document the movements within a business or organization. Business process DFDs were created for the purpose of developing application software and they describe about the data sources, destinations, flows, data storage and transformation.

DFD contains five basic constructs namely: Activities (processes), Data Flows (arrows), Data Stores, External References and Physical Resources.

1. Activities or Processes:

An Activity describes an action that transforms or manipulates the data flows within the system or resources. Simply processes are transformations, changing incoming data flows into outgoing data flows. These activity boxes are generally rectangular, rounded corner ones and often labelled with a noun like a name of a system or an object rather than a verb as with the case in Process Flow Modeling. These Process boxes are divided into three sections, identification number, optional location or the role responsible for the process and the process name.

2. Data Flows or Arrows:

In Business Process DFD, arrows represent the flow of data between activities, data stores and external references with the arrowhead showing the direction of flow of data from source to destination.

In DFD, arrows can be split into multiple branches, and each new branch can re-labeled in order to reflect the decomposition of the data being processed. In the same way, arrows can be merged to show the aggregation of data.

3. Data Store:

In Business Process DFD, a data store represents a database, file or any other data store physical or logical.

4. External References:

In Business Process DFD, external references refer to any location or entity that acts as a source or destination of the data which are external to the scope. Only those entities which acts as a source or destination of data are represented on a DFD.

5. Physical Resources:

In Business Process DFD, physical resources represent the flow of physical objects like material movements and are represented as broad arrows. These differ from the data flows (arrows) in a way that these describe the actual flow of resources related to the information carried by the data flow arrows.


Business Process

Business processes are a set of activities involved within or outside an organization that work together to produce a business outcome for a customer or to an organization.

An organization may have specific goals, aims and targets to be achieved. For products to be manufactured or sold or serviced, there are several activities involved with this organization like employees recruitment, machinery installation, purchasing goods, manufacturing of products, selling and servicing the product to consumers/vendors, collecting the payments and implementing governments rules etc., and these activities collectively are called as business processes.

Different kinds of Business Processes:

  • Business Processes that are within an organization. (e.g. product manufacturing)
  • Business Processes that are between organizations e.g Mortgage sales by a mortgage company and escrow (payment of insurance and taxes) servicing for that mortgage done by some other company. These are called business to business transactions and are done through application interfaces.
  • Business Processes that are managerial.(HR and Recruitment process)
  • Business Processes that are operational.(service calls attended in call centers, information stored by bank tellers regarding opening an account etc.)
  • Business Processes that are activity oriented: The transformations that takes place in a data warehouse.

Process Flow Modeling

Process Flow Modeling is used to graphically describe the various processes that happen in an organization and the relationships between them.


IDEF3 is a process description capture method used in Process Flow Modeling, designed to model and document the processes. This method helps to capture and understand the different processes or activities and their relationships in a system. IDEF3 workflow models explain the activity inter-dependency and timing, branching and merging of process flow, choice, looping and parallelism in much greater detail.

Process Flow Model is a collection of several activities captured with the help of IDEF3 structural analysis method. In IDEF3, each activity is represented by a box with a verb describing an activity or verb phrase describing transformation need to be done by a process and an identification number. For example, Check Credit History, Process an Order, Ship an Order are some of the examples for these. In general, activities take inputs and transform them into outputs or outcomes and the relationship between these activities is represented by arrows. These activities are often referred to as UOW (Unit of Work) within a model.

The main objects or components in IDEF3 are activities or processes, one or more junctions and arrows. Junctions are nothing but a small box that enable branching or joining of processes. The practical implementation of these junctions are represented in detail below.

Fan Out Junctions:

Fan Out junction branches a single process or activity upon entering a junction into several activities (i.e) single arrow enter these Fan In junctions and multiple arrows come out of these junctions.

Fan In Junctions:

These junctions consolidate various processes or activities upon entering these junctions and outputs a single activity (i.e) multiple arrows enter these Fan In junctions and only one arrow comes out of these junctions.

Fan In and Fan Out junctions are often accompanied with several options like AND, OR, XOR, Asynchronous and Synchronous. These AND, OR and XOR are represented visually inside the junction boxes as &, O and X respectively. Asynchronous and Synchronous are represented as lines inside the boxes. Table shown below represents the meaning of these in case of Fan In and Fan Out Junctions.

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Business Process Modeling Methodology | IDEF Modeling Methods

Business Modeling Methods:

IDEF: IDEF is an acronym for Integrated Definition.

IDEF0: IDEF0 is a method used in Business Process Modeling, designed to model the decisions, actions and activities of an organization or system. Diagrams are based on simple box with arrow graphics and text labels.

IDEF3: IDEF3 is a method used in Process Flow Modeling, designed to model processes and documenting the processes and it explains how a system, process or an organization works.

IDEF4: IDEF4 is a method designed to model object oriented programming.

Data Modeling Methods:

IDEF1X (Integrated Definition for Information Modeling notation) and IE (Information Engineering notation):

IDEF1X and IE types are focused on the actual data elements present in a relational database. IDEF1X and IE use different symbols to represent entity and table relationships for designing relational databases.

Dimensional Modeling Notation:

This is a method used for designing data warehouses and data mart.


Business Process Modeling Example

As we know, a business process modeling is a collection or group of related activities or business processes that produce a specific service or product.

In order to explain a Business process modeling in a simple manner, let us assume an activity of getting a seat in a college.

The following diagram shows the different activities or business processes associated in getting a placement in a college. The related activities are grouped on each side marked with different arrows.


Business Process Modeling Example Diagram:

Business Process Modeling Example

  • To obtain a seat in a college, first the applicant need to submit an application along with GRE and TOEFL scores, school mark sheets, birth certificate, payments etc. In Business process modeling, these are represented as inputs with arrows pointing inwards.
  • In order to process the application, college should have computing systems; employees, accounting systems etc., and mechanism arrows represent these.
  • The application should only be approved upon satisfying several factors like; legal requirements, government rules, valid mark sheets etc. and control arrows represent these.
  • When all processes are completed, the applicant will be notified of the selection, scholarships, books etc and output arrows represent these.

Business Process Modeling

Business process modeling is a collection or group of related activities or business processes that produce a specific service or product. Business processes are visually represented as diagrams of simple box with arrow graphics and text labels, better known as Business Process Models.

Business Process Modeling Overview:

Business Process Modeling (IDEF0) is the first step in Business Modeling and it is followed by Process Flow Modeling (IDEF3) and Data Flow Diagrams (DFD). In Business Process Modeling, an organization’s functions are represented by using boxes and arrows. Here boxes represent activities and arrows represent the information associated with an activity. Input arrow, Output arrow, Mechanism arrow and Control arrow are the different types of arrows that are used in business process modeling.

The business process modeling is started with a context diagram and it provides a brief overview about the organization’s activity. In order to understand the activities of an organization in a detailed manner, the context diagram is then decomposed into many sub activities diagrams.

Business Process Modeling Diagram:

Business Process Modeling Diagram

Similarly decomposition of context diagram is done in process flow modeling and data flow diagrams. Context diagram is similar to a conceptual data model in data modeling. The following example gives the layout of the context diagram.

Business | Data Modeling Types


Modeling is an efficient and effective way to represent the organization’s needs; It provides information in a graphical way to the members of an organization to understand and communicate the business rules and processes.
Business Modeling and Data Modeling are the two important types of modeling.

Business Modeling Types:

  1. Business Process Modeling: 

    Business Process Modeling is an analysis of business processes, often represents a collection of activities that are related to each other. Business Process Modeling is explained in detail under the topics Business Process ModelingBusiness Process Modeling Example.

  2. Process Flow Modeling: 

    Process Flow Modeling is used to graphically describe the various processes that happen in an organization and the relationships between them and it is also known as Work Flow Modeling. A typical Process Flow Diagram contains, several related processes often referred to as UOWs (Unit of Work) in Process Flow Modeling, Arrows and Junctions. Junctions are simply boxes facilitating the branching or joining operation between processes that enter or leave a junction. Process Flow Modeling is explained in detail under the section Process Flow Modeling.

  3. Data Flow Modeling: 

    Data Flow Modeling focuses on the flow of data between various Business Processes. A typical Data Flow Diagram contains activities, arrows, data stores and external references. Data Flow Modeling is explained in detail under the section Data Flow Modeling.

Data Modeling Types:

These Data Modeling types and their concepts are described in detail under the Data Modeling section.


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