Information & Technology Management Standards

System Function Model

The System Function Model consists of a detailed functional specification of all the functions to be carried out by the computer system. The specifications for each function should include the following elements:

  • Manual Interaction which, for a computer-assisted function, describes any manual operations that are also required to perform the function.
  • Function Interfaces which specify the interfaces that the function presents to other functions and to the outside world, including users. It defines the data to be passed across the interface and the type of interface. The types for a user interface might include, for example, GUI screen, wall-board display, voice response.
  • Function Description and Logic which provides narrative description of what the function does. Where a function is particularly complex, this component should include a structured representation of its algorithm. The description should also record any mathematical formulae used for calculations. This component must also specify the frequency with which the function is to be performed and any constraints or targets for elapsed time.
  • Function-Data Usage specifying the data (within the System Data Model) that is accessed by the function. This may be specified by means of a CRUD matrix, a data flow diagram or data access path diagrams.
  • Location Information specifying in which geographic locations and on what machines the function is to execute.

Template

Contact
  System Function Model Senior Application Analyst

Deliverable Reviewers

IMG Reviewers

Other Typical Reviewers
Application Analyst ITMB Business Analyst
Data Architect Client Lead

Related Deliverables

Prerequisite Deliverables

Successor Deliverable
  HL Business Function Model Download Template Application Architecture Document
Download Template Technical Architecture Document    

Related Standards

Requirements Modelling and Specification Guidelines and Standards
A risk and controls review must be performed and documented for a new financial system, and whenever there are significant modifications to an existing financial system. Qualified, independent and objective parties must carry out the review. See Financial Systems and Controls in the Core Policy Manual.

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