Extracting requirements for the IMS system

Analysis of the scope and impact of an application in the online environment occurs during the design phase, as well as when application changes are proposed.

You must assess the detail of the application requirements by reviewing the following sources:

• Program specifications and logic
• Implementation plan
• Summary of business requirements
• Design change requests

When you examine application documents, you must extract several kinds of information:

• Requirements for IMS function
• Database requirements
• Predictions of the application workload
• Network definition requirements
• Security considerations
• Operating requirements
• Audit and history recommendations
• Performance factors
• Terminal requirements
• FPBUF requirements

If your system must use intelligent remote stations, you must:

• Select features of IMS that can be used to support distributed application processing (for example, ISC, MSC, LU 6.2).
• Identify the terminal support provided by IMS (including ETO).
• Identify the Fast Path requirements of your system.
• Evaluate the off-loading of application requirements to intelligent remote stations and the use of special components or screen formatting.
• Assist in the design of programs that reside in intelligent remote stations and communicate with IMS; identify the Systems Network Architecture (SNA) protocol to be used by IMS and the intelligent remote station.