Biomedical Engineering Reference
In-Depth Information
Typical Software Development Model
1 Software
Requiremen
t
Generation
2 Concept/High
Level Design
3 Fe
a
ture
Interfac
e
Design
4 Low Level
Design
sequence
(logic)
5 Coding
6 Unit Test
7 Integration
8 Software
Validation
low
details
high
Figure 5.4-1 Typical software development model.
rather than on output of every phase of development.
Another document, called the SQAP, is used to cover
other verification and validation aspects of product de-
velopment, such as software requirements reviews,
hazard and risk analysis, and design reviews.
Using the model as shown in
Figure 5.4-1
, software
validation testing covers validation of the software
product by testing against the requirements generated
in the requirements-generation phase. Software valida-
tion is analogous to black box testing. Integration test-
ing covers verification of features defined from the
requirements-generation phase, the concept/high-level
design phase, and the feature-interface design phase.
Integration testing tests the collection of software mod-
ules, where the software modules are joined together to
provide a product feature or higher level of functionality.
Finally, unit testing covers verification at the lowest level,
which includes the feature interface design phase and the
low-level design phase. Unit testing typically covers the
verification of smaller collections of software modules.
resources; responsibilities; and any special tools, tech-
niques, and methodologies.
The organization describes who is responsible for
carrying out the various verification and validation ef-
forts. In practice, this section is used to describe who will
be responsible for maintaining the laboratory, who will
manage the validation testing, who will manage verifica-
tion testing, and who will be responsible for anomaly
resolution.
Verification and validation scheduling is very impor-
tant for planning activities in order to support the overall
product schedule. Often, a higher-level schedule is
entered into the SVVP, and a detailed schedule is
maintained apart from the SVVP. This is generally due to
different software applications for generating a schedule
and for generating documentation.
The resources section describes all of the equipment,
software, and hardware that are required, to perform
verification and validation activities. A subsection also
should be included on the validation of using any soft-
ware tools, where the software tool is used as part of the
verification and validation process. Per the FDA's regu-
lations (FDA, Quality System Regulation, 21 CFR Part
820, June 1, 1997), any device that is used in a company's
quality system must be validated. A test fixture or
a customized software application clearly falls under this
definition. Thus, it is necessary to validate the software
tool.
Verification and validation overview
This overview describes many of the project management
details that must be addressed in order to perform the
verification and validation functions. They include the
verification and validation organization; a schedule;
