Verification system development

The prototype of verification system of ultrasonic flaw detector developed is described in the scheme given in figure 2. The verification operators performed with the system are as much automated as possible. The level of automatization is limited by the necessity of human reading of information on flaw detector screen, or other operations as manual adjustment of flaw detector settings. 

The automatic acquisition and analysis system we developed within the scope of the Super-Phenix steam generator tube inspection by ultrasonic arrays is a remarkable example of an exhaustive acoustic verification system. It works for every type of probe for tube inspection. 

Within the CQP concept we distinguish three parts (1) basic preparations, (2) CQP monitoring system development, and (3) documentation and verification development, all of which are explained in more detail below. 

GLP regulations require QA personnel to inspect/audit each study conducted, but the extent to which QA personnel are involved in software development and the val-idation/verification process varies from company to company. In some companies, there is little or no QA involvement in these processes, whereas in others QA personnel are involved. QA personnel can provide assistance in the area of vendor audits for purchased software or can conduct inspections of in-house software development to ensure that internal procedures are being followed. QA personnel, who conduct in-process inspections and review the resulting data and validation report for accuracy, could provide inspection support during the validation and verification process. During system development and validation, properly trained QA personnel can provide the regulatory advice needed to ensure that the system will meet government standards. QA personnel become more familiar with the system(s) that will be used when they are involved early in the validation process. 

One of the ideas under investigation concerns a reasonable use of formal methods. Experience of using the formal way of systems development, verification and its quality assurance is extending. Formal methods, in general, are used for ... 

Customer support Quality management/standards Software/system development methodology Testing methods/verification and validation Technical personnel... 

With current system improvements in development, a device that automatically detects, classifies with high probability, and extracts a sample which is diverted directly to an automatic rapid test verification system, all without operator intervention, will soon be commercially available. Combined with a suite of other chemical, toxin, and radiological real-time sensors and an integrated data analysis and alert response system, the ultimate water security system is quickly becoming a reality. 

This chapter provides an overview of expert-system verification and validation (V V) techniques. Several methods are presented. First, many of the conventional software V V techniques such as requirements analysis and unit testing can be applied to expert-system development. Second, an expert-system developer can use automated tools to test rule consistency and structure. A more viable alternative, however, is for the developer to create his own set of consistency and completeness tests. Finally, a developer should rely on qualitative judgment to determine the validity of a knowledge base. This judgment could include expert opinion as well as specialized tests designed to determine knowledge-base certification. The chapter suggests that methods should be combined into an optimal mix in order to best undertake V V. 

Secondly, over the last decade a considerable number of traditional chemical firms were broken up and replaced by so-called industrial parks. This poses a potential problem for verification under the CWC as the Convention s definitions that form the basis for the verification measures assume the existence of plant sites - which were prevalent in the late 1980s, when the CWC was negotiated. A good example of this trend is the evolution of the former Hoechst AG near Frankfurt, Germany, into an industrial park with more than 75 international life science and chemical companies, employing more than 22,000 people.51 In order to maintain an effective and efficient industry verification system under the CWC, developments like these have to be monitored closely, so as to be able to adapt the verification procedures to the changed environment. 

Given the above mentioned impact of past developments in chemical technology and industry on military CW production programmes, verifying the permitted uses of toxic chemicals and related facilities had to assume an important role in the overall verification system of the CWC. Activities not prohibited under the CWC are dealt with in Article VI of the Convention and in Parts VI to IX of the CWC s Verification Annex. While the first three of these parts are informed by the subdivision of toxic chemicals into Schedules 1 to 3, Part IX of the Verification Annex deals with other, unlisted, chemicals -so-called discrete organic chemicals or DOCs - and other chemical production facilities (OCPF), which might be easily adaptable to CW production. 

Requirements Engineering (also known as System Engineering) is the process of eliciting individual stakeholder requirements and needs and developing them into detailed, agreed requirements documented and specified in such a way that they can serve as the basis for all system development and certification activities. There are three core activities associated with robust Requirements Engineering, which are requirements allocation (see the following sections), requirements validation (see Step 2) and requirements verification (see Step 3). These are illustrated in Fig. 1.3. 

To get an even higher level confidence the generated proofs are mechanically checked using the Prototype Verification System (PVS) (Rushby 1993) for which we have developed an ITL proof checking library (Cau and Moszkowski 19%, Cau etal. 1997). 

In (Cau and Moszkowski 1996) we have embedded the ITL proof system within the Prototype Verification System (PVS). Some of the proofs generated in the paper are mechanically checked, see appendix for the ITL specification of the EP/3 encoded in PVS using the ITL library. Part of the refinement calculus of (Cau and Zedan 1997) has also been incorporated into PVS, so that refinement can also be mechanically checked (Cau et al. 1997). Furthermore a link between PVS and the Tempura simulator will be built which allows executable ITL specifications derived with PVS to be executed. So a general development tool is constructed in which you can verify, refine and execute TIL specifications. 

A common tool for requirements management is IBM Rational dynamic object oriented requirements system (DOORS). It is an object oriented requirement system developed by Telelogic, but currently provided by IBM. DOORS supports optimizing requirements communication, collaboration and verification [46]. It is designed as a requirements management application applicable both within a company as well as within the supply chain. The main industrial areas of application are in automotive and space and aviation. 

The main objective during systems development is the achievement of stakeholders concerns, who may be customers, owners, vendors or any person being related to that system. This is done by designing and integrating methods and models within the system, but also with other systems. Integrating means to network the break down strucmre of the diflFerent sub-systems, components and processes involved. Based on this, verification and validation which are two major tasks are to be performed in order to ieali2e the quality standards [9]. 

New technologies for safeguards purposes could address missing capabilities in routine verification tools and could enhance the effectiveness and efficiency of present verification systems. Instrumentation based on new technologies might be in its final development stage... 

Both lEC 61508 and DEF STAN 00-55 mandate software development processes, with the implication that following the prescribed development process is essential to developing software of the required integrity. The use of Commercial off-the-shelf (COTS) software is increasingly prevalent in safety-related systems. However, the approaches prescribed by lEC 61508 and DEF STAN 00-55 cannot be used for COTS software, for which the system developer has little or no control over the development processes adopted. Furthermore, source code may not be available for COTS software, and hence many of the verification techniques recommended cannot be used. 

---