Briefing Study: Requirements Analysis and Specification (slide 19)
How the Feasibility Study breaks down
Technical System Options may be provided by the supplier, or, at this higher level, by an internal IT department. They may be heavily constrained by the existing IT architecture. For example if Windows 8 is the current desktop, already in a networked environment with Oracle application servers. Maybe there are already plans in place to install WIndows 10? Maybe there's an architecture already in place around securing electronic communications that must be used?
The DFM is produced in two or three variants and the LDM in two:
- the first variant (DFM & LDM) describes the current environment and services,
- the second variant (DFM) is a logicalised view of the same
- the third variant (DFM & LDM) is often produced to support the
to-be environment and services for each of the proposed Business System
They are produced from the second, modified by taking into account the requirements to be met by each option.
During Prepare for Study, the first variant is produced at a high level.
During Define The Problem this is logicalised to remove anything present purely to support how things are presently done
During Business System Options, the first part of Select Feasibility Option, a number of versions of the third variant are produced, one for each of the options being developed in conjunction with the business.
Good Practice tip
Always have a Plan B
Why? Even Robert Burns knew the answer to that one:
The best laid plans of mice and men gang aft aglay
Definitely worth remembering ;)