The Software Development Life Cycle - Software Testing: Testing Across the Entire Software Development Life Cycle - page 48

Design the user interfaces ( input and output )
User interfaces often take the form of an interactive dialog consisting of both input
and output. Within this framework, the output is a logical place to begin because the
fundamental purpose of the system is to produce some type of output. In considering
both output and input interface design, the developers evaluate the various display
devices and how they are to be used.
Design the procedures
This design considers all of the functions both from the business perspective (sales,
orders, and payments) and the technology perspective (shared data, security, and
backup/recovery).
Design the data
Attention is given to the nature of the data that the system must store and how it will
be stored (the structure and the devices).
Design the interfaces with other systems
With the input, procedure, output, and storage components designed, attention can
turn to how the system will interface with other systems on the same computers, on
other computers operated by the fi rm, and on other computers external to the fi rm
(suppliers, vendors, shippers, and large customers).
Design the system controls
Controls must be built into each component to ensure that at audit time it can be
proven by update logs that the system performs as intended.
Design the software
Determinations are made concerning how the component designs will be carried out
with software. Both the processes and data of the new system are documented using
the same tools that were used in documenting the existing system in the analysis
stage. Then, programming languages and standards are chosen that afford the
developers the best ways to express the new processes and data in lines of computer
code. Both language richness and maintainability are factors in this determination.
2.7.2 Evaluate the Feasible Designs
When the Figure 2.11 framework has been followed for each of the feasible designs,
they are then evaluated collectively by comparing and contrasting the advantages and
disadvantages of each. An effective approach to this collective evaluation task is to