Business Analysis Techniques - Process Modelling - Context Diagrams - Part One

Business Analysis Techniques - Process Modelling

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There are many techniques that can be used in Business Analysis.

One part of this toolset is modelling techniques - diagrams with supporting text, often used to model business processes and business data.

Process modelling helps us to understand how a business system works now (as is) and possible areas for improvement.

This helps to identify requirements for a new system, analyse those requirements and produce models showing how a new improved system might work.

There are many process modelling techniques that might be used to achieve this.
This post focuses one of the simplest - Context Diagrams.

Context Diagram – What it is:

• A diagram showing flows of information into and out of a business system.
• Defines a boundary between the system and its environment, showing the entities that interact with it and how they interact.
• Provides a top level view of things and so is a useful starting point for further process analysis.

Here is an example - a Context Diagram for a Hotel Booking and Administration System.

Context Diagram - Hotel Booking and Administration System

This may be be slightly confusing at first sight - but do not be concerned. This post and subsequent posts on the topic will explain step by step how this diagram is constructed and what it shows

To start - the box in the centre of the diagram represents the system that we are investigating and analysing - in this case - "Hotel".

The ellipse shapes around the outside represent External Entities, sometimes called "Actors" (particularly in UML - Unified Modelling Language). Essentially - anybody or anything that interacts with the system. In this example - one of these is "Customer".

The arrows show interactions between the External Entities and the system, flows of data, with the arrowheads indicating the direction of the flow.

Context Diagram - Hotel Booking and Administration System

For example - here - Customers make Bookings with the Hotel and receive a Booking Confirmation in return.

Hotel - System.
Customer - External Entity (or Actor).
Booking - Data Flow.
Booking Confirmation - Data Flow.

The content of these data flows, what triggers them, how frequent they are, any business rules that apply - and so on - can be analysed in more detail later for on. A Context Diagram just aims to show a top-level view of a system.

So to summarise:

Context Diagram – What it is:

• Defines a boundary between the system and its environment, showing the entities that interact with it. .… those interactions are shown as data flows.

• Provides a top level view of things and so is a useful starting point for further process analysis.…. the box in the centre – representing the system can be broken down further later on.

Context Diagram – When it might be used:

• Could be used at any time.
• Often used early in a project to understand the current system.
• Can be used later as part of a specification for a new system..

Context Diagram – Why it is useful:

• Helps to understand more about a business system and how it works.
• Helps to define the boundary of the system under investigation – scope.
• Can be validated with business users and other stakeholders relatively easily.
• Helps to understand requirements for a new system.

So that covers three of the classic questions - What, When and Why.

The Who and the How will be covered in future posts.

If you have any questions - please comment below or get in touch.