TRADITIONAL SOFTWARE DEVELOPMENT PROCESSES - Software Design for Six-Sigma: A Roadmap for Excellence - page 29

XT, 2008). In addition to the updated content, the following specific improvements
and innovations have been included:
Simplified project-specific adaptation—tailoring
Checkable project progress steps for minimum risk project management
Tender process, award of contract, and project implementation by the customer
Improvement in the customer-contractor interface
System development taking into account the entire system life cycle
Cover for hardware development, logistics, system security, and migration
Installation and maintenance of an organization-specific procedural model
Integration of current (quasi) standards, specifications, and regulations
View-based representation and user-specific access to the V-Model
Expanded scope of application compared with the V-Model 97

2.3.1.5.1 Advantages

Decisive points of the project implementation strategies predefine the overall
project management framework by the logical sequencing of project completion.
Detailed project planning and management are implemented based on the pro-
cessing and completion of products.
Each team member is allocated explicitly a role for which it is responsible.
The product quality is checkable by making requests of the product and provid-
ing an explicit description of its dependence on other products.

2.3.1.5.2 Disadvantages. None that we can spot. It is a fairly new model mostly
used in Germany and hence yet to find out its disadvantages.

2.3.1.5.3 Suitability. With the V-Model XT (2008), the underlying philosophy
also has developed further. The new V-Model makes a fundamental distinction in
customer-contractor projects. The focus is on the products and not, as before, on
the activities. The V-Model XT thus describes a target and results-oriented approach
(V-Model XT, 2008).

2.3.1.6 SpiralModel. Figure 2.3 shows the Spiral Model, which is also known as
the spiral life-cycle Model. It is a systems development life-cycle model. This model
of development combines the features of the Prototyping Model and the Waterfall
Model.
The steps in the Spiral Model can be generalized as follows (Watts, 1997):

1. The new system requirements are defined in as much detail as possible. This
usually involves interviewing several users representing all the external or
internal users and other aspects of the existing system.