Strategic Workshop on

Enterprise Integration and Enterprise Computing

(Systems and Software Engineering Standards

in the Context of Enterprise Integration) 

19-20 November 1998, Sanctuary Cove

 POSITION STATEMENT

Jim Welsh

Software Verification Research Centre

University of Queensland

Australia, 4072

Email: jim@it.uq.edu.au

(Australian representative on ISO/IEC JTC1 SC7 WG9)

 Abstract

Integration of the management of operational risks (and the consequent system integrity requirements) with the ‘normal’ systems and software engineering life cycles is an ongoing concern of Working Group 9 of ISO/IEC JTC1/SC7. This position paper postulates that 

(a) effective integration of risk management is equally important at enterprise level, and

(b) ;useful parallels may exist between this integration of risk management and the integration/interaction problems arising from other enterprise integration concern.

1. Critical systems

Computer-based systems are increasingly used in applications that are critical in some senses, such as safety, security, mission, etc. Fly-by-wire aircraft, heart pacemakers, military or diplomatic communication networks, industrial process control are typical examples of such applications. Containment of the risks inherent in the application of these systems is a dominant consideration in their development.

One simple approach to development of such systems is to decide whether the overall system is critical or not, and if so to apply highly rigorous development techniques to all parts of the system. A system deemed to be non-critical may be developed using less rigorous techniques. This approach can be seen as ascribing to the system one of two integrity levels. A high-integrity system requires a high-integrity development process. A low-integrity system allows a low-integrity development process. Because of the disparity in techniques and processes involved, the two lifecycles can effectively be considered as disjoint.

A more sophisticated approach, increasingly used in critical systems development, is one which

1. recognises multiple integrity levels, each with their own development requirements, and
2. recognises that different (hardware and software) components of the system may be ascribed different integrity levels, and be developed using different techniques.

 This necessarily implies a more complex life cycle model which is capable of accommodating and reconciling the variation in integrity levels and techniques involved.

 2. The standards perspective

Development and application of appropriate standards is a key strategy in containing the risks associated with critical computer-based systems. A variety of standards already exist in various application sectors. 

Within the overall activities of ISO/IEC JTC1/SC7, software integrity issues are the specific responsibility of Working Group 9 (Software Integrity). WG9 operates as a joint working group with IEC TC56 WG10 (Software aspects of dependability).

Todate, the joint working group has developed a standard for the determination of system and software integrity levels (ISO 15026). This is a generalisation of the multiple integrity levels process inherent in several existing or emerging sector standards, and is specifically designed for application in multiple risk dimensions (safety, security, mission, etc.).

The working group is now working on guides to the achievement of the requirements implied by integrity levels in the development of software components, but a key factor in the success of its efforts is achieving consistency between its own products and those of SC7 as a whole. With ISO 12207 (Software Life-Cycle Processes) currently under revision and ISO 15288 (System Life-Cycle Processes) under development, ensuring the consistency of these standards with the integrity management process inherent in ISO 15026 is a particular current concern.

3. An enterprise perspective? 

In the context of the Strategic Workshop’s objectives, the preceding review of critical systems processes and standards provokes the following observations:

1. Risk management is clearly a concern at enterprise as well as systems level. Comparison of how risk management is catered for at each level may usefully inform both communities.

2. Useful parallels may also exist between the way in which risk management is handled at enterprise and system levels, and the way other concerns are reconciled in enterprise integration.

Review and discussion of these issues within the workshop can benefit both the enterprise integration and systems/software engineering communities.