User Specification

The HSE publication 'Out of Control' identifies that 60% of incidents within the process sector can be attributed to a lack of specification. That is a lack of a fully defined 'User Specification'. This is a key requirement where microprocessor based process control equipment is to be utilised.

A key element in the design process is the identification of controllability and operability this is achieved by the application of Hazard and Operability reviews at an early stage which includes for a review of the control system by integration of the requirements of a CHAZOP, (Computer HAZOP). To do this fully a User Requirements Specification is an essential information source. (link to CHAZOP)

A recommended guideline for the production of the appropriate documentation and its content is the Institution of Electrical Engineers -Guidelines for the documentation of computer software for real time and interactive systems.

One of the key elements in the guidelines is the User Requirements Specification written by the user in which are defined clearly and precisely what is required of the system. These are defined in terms of Function, what the system must do and Interface how the system will connect to and interact will its external environment to meet its functionality. Some of the requirements in this document are:

Overview.

Identifies the relationship of the system within the total plant scheme and the overall scheme objectives.

System Objectives.

Full detail of objectives to be achieved by the system as they relate to its operational requirements.

System Interfaces.

Details the physical interfaces with its environment and the human operator.

The human interface specification is a critical requirement and addition guidance on this can be found in Engineering Equipment and Materials Users Association, (EEMUA) publication - Process Plant Control Desks Utilising Human-Computer Interfaces, a guide to design, operational and human interface issues.

Rowan House Ltd has the experience and know-how assist you in the production of this vital document which will be a core document for your enquiry and supply contract. It will also form the basis for your system guarantee.