This video describes the features of the context diagram, including common symbols, formatting options, and the instances where you would apply each of them.
- Ask any great photographer and they'll tell you that you need certain building blocks to create an awesome shot. Lighting, structure, depth, and good subject matter and a moment in time that they wish to capture through their lens. Photographers also use different lenses for different distances and expected detail. Context diagrams represent the overall panoramic photograph depicting the highest level. The following definitions assist in framing the context diagram.
Context: how a business area, system, process, organizational area being analyzed, interacts with the world. Actor: a person, department, or system that is directly involved with the business area being analyzed. External entity: a person, department, organization, or system that interacts with the business area but is not being analyzed. They can be the source or destination of data outside of the system.
Analysis considers only the inputs or outputs, but does not review the external entities, processes, or systems. Context diagrams also leverage three common components or building blocks. Entities, relationships, and processes. All of which are needed in creating that perfect, high level diagram. Entities are the elements or actors that represent each player that fits within the context of the diagram.
They can be shown in any way that provides clarity and helps the reader identity them easily. It's not uncommon to see these entities represented and labeled in boxes. Within those boxes you might find ovals, stick figures, or even graphics or clip art, as long as it fits within the message you wish to convey. However, when creating a context diagram for the organization you're analyzing, you would use a circle to represent the main entity and use boxes around the outside to represent the external entities.
A circle is used as it indicates what you have control of. In this case, what goes on internal to your organization lives inside the circle, whereas a box indicates what your organization only has an influence over. It's all very well and good to have all the entities identified. What really provides the context we are looking for are the relationships between each of them. This is done with arrows, or flows. The flows represent the relationship between the two entities.
The direction of the flow indicates whether the interaction is incoming or outgoing. These flows represent activities that the analyzing organization must perform and adhere to to ensure smooth interactions that pass between the two entities. One entity is sending an activity, also known as an output and one is receiving the activity and these are called inputs. Good modeling standards dictate that each relationship starts from one entity and finishes at another.
The customer flows here clearly show incoming and outgoing interactions between the customer and the organization. These are the processes needed in achieving the expected outcome of the external entity. Each arrow represents the flow of information, data, products, artifacts being sent, between the organization and the external entity. These flows should be labeled to provide further context. Always remember to keep your context diagram at the highest level.
Rather than having a flow for each interaction, you can simplify a diagram by listing all the types in interactions on a single flow. These single flows represent the process. These processes can each be analyzed separately and drilled down to into more detail when you create your functional flow diagram. So just like framing that perfect photograph, the best context diagram are simple, clear, uncluttered, and usually fit on one page. By utilizing the three fundamental features of a context diagram, entities, relationships, and processes, you start your business process modeling at the highest level and creates the foundation for future and more detailed analysis.
Context diagrams are the pictures in which the organization fits with the outside world and becomes the diagram that is worth more than a thousand words.
- Using common modeling tools
- Determining when to use a particular modeling diagram
- Avoiding the pitfalls associated with each diagram
- Creating diagrams
- Leveraging key stakeholders