Q2 Safety related / safety critical system design

[PJW]

[b]Question 2.
Define what is meant by

[Hort]

I have had an attempt on this one.

[PJW]

I have had an attempt on this one.

We'll be discussing the various attempts at this question tomorrow and I'll then post the other offerings, perhaps with an overall summary of the different approaches and content.

[PJW]

I have now added the attempted answers to this and all the other questions in this section.  They were done in exam conditions, though some certainly took over 30 mins, because people's time management wasn't as strict as it should have been, so others would have suffered accordingly- NOT A GOOD EXAM POLICY.
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Regarding Hort's attempt, I thought that it was good.

A bit light re the definitions; there were 6 marks available for this and not enough written to justify earning all these.

The examples though were good and I think ought to have scored very well.

Minimising failures was covered well, but the reduction of hazardous effects was rather thinner, although what was there was quite good.
Actually I think that this was partly misallocation of material between these sections; I'd have kept part a) strictly to reducing the occurrence of any failures (including those of sub-systems which don't give a system level failure) and therefore I could have put in part b) the duplication / redundancy type issues.  However the material was all there and marks allocated across the two, so in this instance of no consequence; but worth bearing in mind for other exam questions that you could potentially choose to interpret "failure" to mean either of these things (if the question doesn't otherwise clarify).

I have added comments in the answer attached here, many of which are more aimed at explaining further so that people can learn and understand more of the subject, rather than suggesting that it was all necessary content for this particular answer.  
Some though are suggestions that I feel would have further improved the answer; I think as presented that the answer would probably have been a Credit, but it could relatively easily have been made into a Distinction.

I have added a few lines in tracked changes- these I think are the most important additions / changes.

I have had an attempt on this one.

We'll be discussing the various attempts at this question tomorrow and I'll then post the other offerings, perhaps with an overall summary of the different approaches and content.

[veishal]

There are three aspects which can be applied to aid the engineering software for life-critical systems. First is process engineering and management. Secondly, selecting the appropriate tools and environment for the system. This allows the system developer to effectively test the system by emulation and observe its effectiveness.