In this paper, part of a Master’s Thesis at the University of Lappeenranta, Teemu Koskinen provides a thorough overview of the SRTP regulation, requirements and the challenges faced in assessing systems. Highlighting some of the weaknesses of traditional approaches (Failure Mode and Effect Analysis – FMEA) such as liability to human error and inflexibility to modification as designs develop, Teemu considers the possible advantages of an analysis through a software tool such as Systema™.
Teemu notes the specific issues associated with traditional analysis: … crucially the requirement to fully consider the interdependencies of multiple systems is impractical and laborious in a human driven paper based FMEA analysis.
Aly Douglas
The author examines the SRTP regulations and internationally recognised standards for reliability assessment and therefore presents a good base for assessment and best practices, including a consideration of their limitations. In particular, Teemu notes the specific issues associated with traditional analysis: the difficulty to accurately deal with the scale of ship systems, the large number of casualties, the difficulty in performing the evaluation numerous times as the design evolves, and crucially the requirement to fully consider the interdependencies of multiple systems is impractical and laborious in a human driven paper based FMEA analysis.
The use of Systema™ as an alternative methodology is assessed through the consideration of three specific systems: power distribution, fire detection and UHF. Some of the key modelling features and processes are highlighted, and Teemu further shows how the software can be used to build up a system model and how the results can be interpreted. He identifies that one of the key advantages of Systema™ is the ability to update the ship model and system model and re-run full casualty calculations with relative speed and ease, making it possible to easily modify and analyse the model as the design evolves. As the calculation can be quickly and easily repeated, it opens up the possibility of a trial-and-error approach to problem solving.
one of the key advantages of Systema™ is the ability to update the ship model and system model and re-run full casualty calculations with relative speed and ease
Aly Douglas
Teemu however identifies the need for some refinement to the treatment of short circuits by the software, in particular cases. After highlighting this, Safety at Sea worked to improve this behaviour and a “short circuiting” cable type has been introduced to address this deficiency – although unfortunately not in time for the thesis’ publication. In the meantime, work is continuing to improve the short circuiting behaviour, and in fact the general damage propagation and containment model, to make it even more flexible.
Another interesting point raised by Teemu is the need to have integrated design solutions to reduce the burden of modelling the systems in Systema™. Generic methods for importing data through an XML data exchange format exist, as well as a scripting capability to automate repetitive tasks. However, tighter integration can be achieved, and Safety at Sea often work with users to help integrate Systema™ with their specific systems and processes through bespoke interfaces.
In conclusion Teemu finds that Systema™ provides a functional alternative to traditional approaches such as FMEA and has some key advantages – the ability to easily update an existing model, a fully interconnected model (interdependencies handled), and ability to easily update results by rerunning calculations – making it easier to test solutions to problems.
Click button below for the full thesis: