High-Level Software Requirements

Although much easier to assemble, a software program written in a high-level language requires more time for the computer to execute, since all the instructions must be translated into machine code before the computer can understand them. Even a simple statement like start in a high-level language requires several machine-code moves to execute. 

Since safety of software cannot be analyzed without taking into account the system context, we take the advantages of STPA at the system level to construct a method for verifying safety requirements derived at the system level by using STPA. The method starts with safety analysis of software in the context of the system level by using STPA to derive the high-level safety requirements and constraints. The potential hazards identified during STPA will be translated into a set of verifiable safety requirements. The safety verification uses these verifiable safety requirements to prove that the software satisfies these requirements. 

Object code verification. Finally, when the control system model has been compiled into object code, it should be verified that the object code correctly implements the control system model. This process can be automated by tools that should also be provided by the framework. Automated object code verification for safety-critical control systems is motivated by the fact that applicable standards for these safety-critical applications, e.g. for railways [3], require a substantial justification with respect to the consistency between high-level software code and the object code generated by the applied compilers. 

Against high levels of computer control Is the pre-batch preparation time required for sequencing, software writing and parameter setting, the full details of the latter of course often not available. This activity Is acceptable as a precursor to full scale production but Is felt restrictive and could Inhibit flexibility In a pilot plant. 

The acquisition software sets up the right hardware parameters to begin an acquisition and controls the data flow during the acquisition. It can be controlled in two different ways, the routine way and the research based way with full access to all hardware based parameters. The routine way of starting an experiment requires the existence of a high level method, which is mainly a software module that translates high level, easily understandable parameters into low level, machine readable parameters. 

The use of fundamental parameters is attractive for various reasons. They impose fewer restrictions on the number of standards required for analysis. This simplifies the standardisation protocol for maintaining a XRF system, and permits greater flexibility in dealing with different types of materials. Inten-sity/concentration algorithms of the fundamental type, i.e. without recourse to the use of standards, have gradually developed [238-240] and are now widely available [241]. Functionality and quality of XRF software have reached a very high level, with a large variety of evaluation procedures and correction models for quantitative analysis, and calculation of fundamental parameter coefficients for effective matrix corrections. Nevertheless, there is still a need for accuracy improvement of fundamental parameters, such as the attenuation functions. 

Provide a high level of confidence that the software code or configuration meets the defined operational and technical requirements of the system design specifications and the URS... 

The implementation of an effective security regime is required to comply with the regulators expectations for control of electronic records. The pharmaceutical manufacturer will be responsible for providing maintenance of the security aspects of LIMS. This is normally accomplished through software protection (e.g., passwords and log-on accounts) but may also take the form of protection through physical restrictions (e.g., locked-up or restricted areas). The management of this function should be in accordance with a formal SOP. The use of passwords and high-level accounts must be strictly controlled to prevent security breaches. Typical examples of control should be ... 

Because of the high level of automation and instrument control, many modem analytical LC/UV/MS instmments have open-access software that enables non-trained users to use the system. In essence, such software needs only to be developed by expert users but once complete, will allow inexperienced personnel to operate the instmment and generate their own data reports without any intervention by trained operators. Trained operators/expert users are only required for system maintenance, troubleshooting, etc. This software gives the appearance that the system is easy to use and also does not require the user to set any operating parameters. Although not fully developed in either case yet, we are currently working on such software for both the autoprep and MS-prep systems. 

Software engineering practices may include documented unit testing, code reviews, explicit high-level and low-level design documents, explicit requirements and... 

The user requirements specification, also referred to as requirements document or release plan, describes the requirements from an operator s point of view. This high-level document does not give any details about how the software actually is constructed, except that it may contain desired user interface designs to address a requirement. 

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