12.5 Documenting The System

Every system development is unique and need unique documentation. There are two basic types of documentation; system documentation and user documentation.

12.5.1 System Documentation

System documentation records detailed information about system's design specification, its internal workings and its functionality (Hoffer et. al., 2005). System documentation is prepared for maintenance person who will in charge the system operating in the future. System documentation can be divided to internal and external documentation.

	Internal documentation
	Internal documentation is part of the program source code or is generated at compile time
	External documentation
	External documentation is a system documentation that includes the outcome of structured diagramming techniques such as data flow and entity-relationship diagrams. Although it don't cover the code itself, but it can provide useful information to the primary users of system documentation-maintenance programmer

12.5 Documenting The System

As stated earlier, system documentation is intended for system maintenance programmer; user documentation is intended for system users. User documentation consists of written and visual information about the system, such as what its function, how its function and how to use it. There are few types of user documentations;

	reference guide - consist of exhaustive list of system functions and commands

	quick reference guide - provide essential information about operating a system in a short, concise format
	user's guide - provide information on how users can use a computer system to perform specific tasks.

12.4 Installation

Figure 12-3: Parallel Installation.

12.4.3 Single-location Installation

Single location also refers to location or pilot installation. This approach is where the organization is trying out to use a new system at one location and use this experience in deciding how the entire system should be deployed throughout the organization as in Figure 12-4. The one site installation is either use direct installation or parallel installation. It's a middle-of-the-road approach compared with direct and parallel installation. Single location can be referring as branch office, or one department. As soon as the location approved the system, it will be install to the other location. At this stage, the installation at other site can be direct installation since all the major errors have been fixed at the first test

12.4 Installation

location. The advantage of using this strategy is it can minimize the potential damage and costs because the successful is determined at the first site. But the disadvantage is, it may take a longer period to install the whole system.

Figure 12-4: Single-location Installation.

12.4 Installation

12.4.4 Phase Installation

Figure 12-5: Phased installation.

Installation may also require a system acceptance test plan. System acceptance test is a final opportunity where end users, management and information system operation decide either to use or reject the system. System acceptance test is a test performed on the final system wherein users conduct verification, validation and audit tests

12.4 Installation

(Bentley et. al., 2007). It covers three levels of acceptance testing:

Verification testing
Verification testing also refers to alpha testing. This testing runs the system in a simulated environment using simulated data. It's looking for errors and omissions regarding end users and design specifications that were specified in the earlier phase of testing.

Validation testing
Validation testing also refers to beta testing. This testing runs the system in a live environment using real data. A number of items tested during this testing such as:

	system performance
	peak workload processing performance
	human engineering test
	methods and procedures test
	backup and recovery testing

Audit testing
Audit testing is a test performed to ensure that the system is free from any errors and ready to be placed at the real location.