(2)System maintenance
The following are key maintenance tasks for preventing failures.
Type of
maintenance
Description
Preventative
maintenance
Remove the causes for future failures before they occur.
Scheduled
maintenance
Perform daily checks. Also, enter into a maintenance agreement with a specialist and request hardware checks once a
month, for example.
Remote
maintenance
Enter into a maintenance agreement with a specialist, and remove causes of failure remotely (remote operation) by connecting the specialist and the user (system user department)
via communication lines.
(3)System failure
In terms of maintaining system operation, it is important to take preventive
measures so that failures do not occur. However, for reasons such as system modification as a result of tax rate changes, workflow changes, or
hardware lifespan, failures in the existing system could occur and further
modification may be unavoidable.
During system development, it is necessary to consider the occurrence of
failures as unavoidable. The key is to be well-prepared with effective
countermeasures that will prevent failures from adversely affecting the entire system or stopping operations.
4-1-2 Software estimation
Reference
FP
Abbreviation for “Function Point.”
Reference
GUI
Computerizing operations requires an awareness of cost when determining
which functions to incorporate into the system.
The following are methods for estimating system development costs.
Type
Description
Characteristics
Program step
method
A method for estimating the
number of program steps
(number of lines) in the entire
system from past records.
Suited to estimations for development of core business
systems with significant accumulation from the past.
FP (Function Point)
method
A method for estimating system development personhours and development costs
by quantifying the number of
input/output screens and files
to be used, and the level of
difficulty of functions to be
developed. Quantified items
are referred to as “function
points.”
Suited to estimations for development using GUI and object orientation.
Refer to “Chapter 9-1-1 Human interface technology.”
Reference
Object orientation
Refer to “Chapter 4-2-1 Software development process and methods.”
125