Real-Time Animator and Requirements Traceability - Using Event-B for Critical Device Software Systems - page 80

Requirement Engineering (RE) techniques are used at the early stages of the
system development life-cycle, which are crucial for successful development of a
system. As the computer systems play increasingly important roles in organisations,
it seems to pay more attention towards the early stages of Requirement Engineering
(e.g., [ 9 ]). The cost of the system development increases more when errors are dis-
covered later phases of the system development [ 8 ]. The basic beginning objective
of stakeholders and the initial requirements statement of requirement engineering
are “what the system should do?”. Incompleteness, ambiguity, inconsistencies, and
vagueness, are the most common problems encountered when eliciting and speci-
fying requirements and to find these common problems are the main goals of any
requirement engineering tool [ 9 ].
A model captures a view of a physical system. It is an abstraction of the physical
system, with a certain purpose. Thus the model completely describes those aspects
of the physical system that are relevant to the purpose of the model, at an appropriate
level of detail. Not only a system developer is required to view a system from several
angles but stakeholders want the same view of the system from different angles
according to the requirements. Requirements traceability is a branch of requirements
management within software development. Requirements traceability is concerned
with documenting the life of a requirement and to provide bi-directional traceability
between various associated requirements. It enables users to find the origin of each
requirement and track every change, which was made to this requirement.
Validation of the requirements specification is an integral and indispensable part
of the Requirements Engineering (RE). Validation is the process of checking, to-
gether with the stakeholders, whether the requirements specification meets the stake-
holders' intentions and expectations [ 39 ]. Animation of a formal specification is one
of the well-known approaches in the area of verification and validation, which pro-
vides visual animation of the formal models. An architecture of the real-time anima-
tion tool is presented in [ 41 ], that allows to check the presence of desired function-
ality and to inspect the behaviour of a specification according to the stakeholders in
the real-time environment.
The contribution of this chapter is to propose a new functional architecture, to-
gether with a direct and an efficient method of using real-time data set, in a formal
model without generating the source code in any target programming language [ 41 ].
Real-time animation helps to design a critical system, which helps a specifier to gain
confidence that the model is being specified, refined and implemented, does meet
the domain expert's requirements. Main objective of this proposed real-time anima-
tion framework bridges the gap among different domain experts. For example, in the
development of a medical system [ 34 ], a formal model that is designed by a software
engineer is not understandable by the medical experts like doctors or medical prac-
titioners due to lack of mathematical knowledge. If a software engineer presents a
formal specification into animated graphics, based on actual behaviour of the formal
specification, then the animated graphics can be simpler and easily understandable
by the doctors, physicians and medical practitioners.