2007, Q6 - Question on Testing

[Peter]

Hi,

I have had a go on a question involving testing. There is not a specific thread set up for this type of question so I posted it here. I don't have "hands on" experience of testing, my knowledge is based on reading standards and reviewing test plans & strategies so would be interested to see how close/far I'm off the mark!

H

I had very similar thoughts about whether you had answered the question that was asked but on re-reading the question changed slightly too. PJW has said much of it, but just to confirm, I think the answer was presented in the wrong order. This was a pity as it was good stuff, perhaps just not the right good stuff.

I thought that the bit on maintenance testing should have more clearly emphasised the fact that you are only testing around the bit that has been affected. This could have been brought out in an explanation of when maintenance testing can be done (it could be part of a new scheme where, say, a signal head is being updated but kept in the same place) and that there is the need to test "just before and just after" the alteration. As PJW said, also, the "previously in and working" premise is very important.

Another area in the works testing bit that I thought would have been in scope of the question would to be consider some of the strategies like "over and back" testing. You tended to assume that what was new could never be tested until the day of the race in the middle scenario.