Context models illustrate the operational context of a system and its interactions with the surrounding environment, often referred to as enterprise architecture or conceptual models. They define the boundaries of the system and include diagrams like the system context diagram, which highlight entities that interact with the system, such as in the case of an automated-teller machine (ATM) system. While context models showcase the presence of other systems in the environment, they do not detail the relationships between these systems and the specified system, necessitating the use of additional models, like business process models.

1. Context Models

2.  Context Models:
Context models are used to illustrate the operational
context of a system.
They show what lies outside the system boundaries.
 They shows how IT applications fit into the context of
the people and the organization they serve.
Context models are sometimes called enterprise
architecture models, sometimes high-level
design models and sometimes conceptual models.
Context Models

3. They simply show other system in environment, not
how
the system being developed in that environment.
Producing an architectural model is first step in
context
modeling.
Social and organizational concerns may affect the
decision on where to position system boundaries
Context Models

4. System Context Diagram
• A System Context Diagram (SCD) in software engineering
and systems engineering is a diagram that defines the
boundary between the system, or part of a system, and its
environment, showing the entities that interact with it.
• This diagram is a high level view of a system.

5. Automated-teller Machine(ATM)
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It illustrates the structure of information system that
include a bank auto-teller network.
Each ATM is connected to
• Account database
• Local branch accounting system
• Security system
• Maintenance system to support machine maintenance.
• Usage database that monitor how the network of ATM is
used
• local branch counter system provide services such as
backup and printing.

6. Example – Context models of an ATM System
Auto-teller
system
Security
system
Maintenance
system
Account
database
Usage
database
Branch
accounting
system
Branch
counter
system
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7. Context models normally show that the environment
includes several other automated systems.
However, they do not show the types of relationships
between the systems in the environment and the
system
that is being specified.
Therefore, simple context models are used along with
other
models, such as business process models. These
describe
human and automated processes in which particular
software systems are used.
Context models of an ATM System

8. Example - Order Processing Data Flow Diagram
Complete
order form
Order
details +
blank
order form
Validate
order
Record
order
Send to
supplier
Adjust
available
budget
Budget
file
Orders
file
Completed
order form
Signed
order form
Signed
order form
Checked and
signed order
+ order
notification
Order
amount
+ account
details
Signed
order form
Order
details

9. References
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