Book Image

The Complete Edition - Software Engineering for Real-Time Systems

By : Jim Cooling
Book Image

The Complete Edition - Software Engineering for Real-Time Systems

By: Jim Cooling

Overview of this book

From air traffic control systems to network multimedia systems, real-time systems are everywhere. The correctness of the real-time system depends on the physical instant and the logical results of the computations. This book provides an elaborate introduction to software engineering for real-time systems, including a range of activities and methods required to produce a great real-time system. The book kicks off by describing real-time systems, their applications, and their impact on software design. You will learn the concepts of software and program design, as well as the different types of programming, software errors, and software life cycles, and how a multitasking structure benefits a system design. Moving ahead, you will learn why diagrams and diagramming plays a critical role in the software development process. You will practice documenting code-related work using Unified Modeling Language (UML), and analyze and test source code in both host and target systems to understand why performance is a key design-driver in applications. Next, you will develop a design strategy to overcome critical and fault-tolerant systems, and learn the importance of documentation in system design. By the end of this book, you will have sound knowledge and skills for developing real-time embedded systems.
Table of Contents (16 chapters)
Preface
15
Glossary of terms

12.2 System Specification Aspects

12.2.1 The Specification Problem – Again

The problems encountered in defining system requirements (specifications) have already been well and truly covered. But let's assume that we have managed to produce a complete statement of requirements (SOR) for a critical system (or so we think):

Figure 12.8: Sources of software-related faults

Now, at this point, some very important questions should be asked:

  • Are the system specifications clear, understandable, and unambiguous?
  • Can we be absolutely sure that they are consistent and complete?
  • Can we, as the specifiers, be absolutely sure that the software designers correctly and fully understand these requirements?
  • Can we review the proposed design to check its correctness (that is, does it meet its specification)?

Note well this last point: the check for correctness. To do this, we compare the program (text) whose syntax is defined formally...