(08-04-2010, 07:50 PM)adikarina Wrote: Hi all,
I am struggling to find some information regarding the different types of specifications and when which type should be used.
Please provide some guidance as where to find it.
Thanks
Aditi
Not surprised; I can't immediately put my finger on one good source. Sure there are several references but I'll need some time to get a selection together; also I think they'll be a need to derive what you need from a composite of sources as background reading rather than a ready written comparison.
For a one-pager, which similarly is ostensibly very little to do with railway signalling, look at this
Slightly more detailed and wider ranging is this one
Perhaps the best I have found so far ; it could almost be an answer to an IRSE question (it is of about the right length and structure); it may not be particular industry specific but had it had some more relevant examples...
Another brief example that I have copied and now paste here:
Two types of specifications are commonly used in contracts dealing with landscape and revegetation projects: Performance and Prescription.
A performance spec merely states what the final outcome of the project should be, e.g., ...perennial turfgrass cover, three deciduous trees per one thousand square yards, drainage that meets all current regulations and industry standards....
Such a specification leaves the method used by the contractor up to the contractor. Successful completion of work will be judged on the basis of the project's outcome.
Prescriptive specifications, on the other hand, tell the contractor exactly what to do and how to do it. He will have fulfilled his contract if he plants three prescribed trees at prescribed spots in holes of a prescribed depth; a 100 pounds of seed X and 50 pounds of fertilizer Y using equipment Z.
Nothing has to actually grow in order to meet the prescription.
Does this begin to get you started- can you relate this to your private life / railway experience?
Do you have a particualr IRSE exam question in mind or does this relate to real work in the day job?
PJW