What does tool integration mean? One can argue it is the ability for different tools to talk to each other and exchange data. Though this may be true from a typical software tool integration, a common definition of integrate, i.e. to bring together or incorporate (parts) into a whole (dictionary.com), indicates that we need to go a bit further.
So what should tool integration mean from a functional safety lifecycle perspective? It would be nice for different tools to talk to each other, but what we would really need is the ability to work on different lifecycle phases with a perspective that the information recorded is recorded in such a way that it will simplify the facilitation of subsequent lifecycle phases.
An example of this is a typical going back and forth between Process Safety information and Safety Requirements Specification when it comes to an unambiguous definition of the safe state or specification of operating ranges and trip points. If this information is available during the Process Hazard Analysis, why not facilitate the documentation during the Process Hazard Analysis and subsequent pre-population of the Safety Requirements Specification. Of course one should still be able to review the information and update if necessary but recording the information when it is available will make the lifecycle activities more efficient.
For the exSILentia® software, this concept is at the core of the platform development. The diagram below provides a simplified view of how data elements interact between different lifecycle phases.
A second aspect with regard to integration of software tools is how these tools relate to real life. In exSILentia there is a clear definition of logical and physical elements. Modeling a SIF during SIL verification is usually a logical process where device models (specific make and model equipment item) are combined to a specific SIF. In a real environment there are specific devices (unique equipment items) at different locations. This concept is highlighted in the diagram below.
The linking of devices to device models is essential as this is the way to provide accurate performance information for each device model.