Context model

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1. CONTEXT MODELS

2. Contents : System Modeling Contex Models Context Diagram System Boundries MHC-PMS ATM

3. SYSTEM MODELLING: System modelling helps the analyst to understand the functionality of system and models are used to communicate with customer.

4. Different models present the system from different perspectives External perspective showing the system’s context or environment Behavioural perspective showing the behaviour of the system Structural perspective showing the system or data architecture

5. Context Models: Context models are used to illustrate the operational context of a system . They show what lies outside the system boundarie s. 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.

6. 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.

7. 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.

8. System Boundaries: System boundaries are established to define what is inside and what is outside the system. They show other systems that are used or depend on the system being developed.

9. The position of the system boundary has a profound effect on the system requirements. There may be pressures to develop system boundaries that increase or decrease the influence or workload of different parts of an organization.

10. 1: Mental health care patient management system (MHC-PMS) In de veloping the specification for the patient information system for mental healthcare , this system is intended to manage information about patients attending mental health clinics and the treatments that have been prescribed. In developing the specification for this system, you have to decide: whether the system should focus exclusively on collecting information about consultations (using other systems to collect personal information about patients) or whether it should also collect personal patient information.

11. Advantage: The advantage of relying on other systems for patient information is that you avoid duplicating data. Disadvantage: The major disadvantage , however, is that using other systems may make it slower to access information.

12. MHC-PMS has a simple context model that shows the patient information system and the other systems in its environment. MHC-PMS is connected to Appointments system . P atient record system with which it shares data. Systems for management reporting and hospital bed allocation. S tatistics system that collects information for research. Prescription system to generate prescriptions for patients’ medication.

13. Context of MHC-PMS:

14. 2: Automated-teller Machine(ATM) It illustrat s the structure of information system that include a bank auto-teller network. E ach atm is connected to A ccount database L ocal branch accounting system Se curity system Maintenance system to support machine maintenance. U s age database that monitor how the network of atm is used local branch counter system provide survices such as backup and printing.

15. Context Of ATM:

16. 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.