This is actually a very tricky question as it is contract law rather than engineering. The general rule with standards is that they, of themselves, are not mandatory, so just because there is a standard does not mean it has to be complied with. What makes a standard mandatory is either the contract or appropriate legislation. (A good example I tend to use is that there are a multitude of standards, national and international, for domestic plugs and sockets. I am pretty sure there is even an international IEC Standard. However from memory there are only two countries in the whole world that use the international standard, and in the UK the British Standard for plugs and sockets (BS1363) is mandated by regulations. Other standards may be used for particular circumstances where the regulations aren't applicable but this is between the supplier and customer.)

In most instances the use of specific standards, where not mandated by national legislation, will be specified in the contract between the supplier and customer. This contract will dictate what revision of the standard and the cut off date, the cut off date commonly being the date at which the contract is signed. However it may specify a particular stage in construction or a particular drawing approval, since when you are half way through construction of a big project it is impractical to go back and do a redesign. As an example, the latest UK aircraft carrier project was started about 20 years ago and there have been many changes in the standards since it started. However the date at which the standard list was frozen (in common with all other ship construction - this is not a special case) would have been the date on which the keel was laid, still more than ten years into the project but it prevents cost over-run due to changes in standards (being a military project they find all sorts of other ways to over-run the cost!)

If you need to find out what amendments are applicable you need to find out what is calling up the standard (contract, national regulation, etc.) and see what is said about what version of the standard is to be used and at what stage the changes are frozen.

If this is a common problem it may be worth getting involved with the committee that updates the standard so that you are aware of what changes are coming through ahead of time (and may even be able to influence the changes).

Alasdair

This is actually a very tricky question as it is contract law rather than engineering. The general rule with standards is that they, of themselves, are not mandatory, so just because there is a standard does not mean it has to be complied with. What makes a standard mandatory is either the contract or appropriate legislation. (A good example I tend to use is that there are a multitude of standards, national and international, for domestic plugs and sockets. I am pretty sure there is even an international IEC Standard. However from memory there are only two countries in the whole world that use the international standard, and in the UK the British Standard for plugs and sockets (BS1363) is mandated by regulations. Other standards may be used for particular circumstances where the regulations aren't applicable but this is between the supplier and customer.)

In most instances the use of specific standards, where not mandated by national legislation, will be specified in the contract between the supplier and customer. This contract will dictate what revision of the standard and the cut off date, the cut off date commonly being the date at which the contract is signed. However it may specify a particular stage in construction or a particular drawing approval, since when you are half way through construction of a big project it is impractical to go back and do a redesign. As an example, the latest UK aircraft carrier project was started about 20 years ago and there have been many changes in the standards since it started. However the date at which the standard list was frozen (in common with all other ship construction - this is not a special case) would have been the date on which the keel was laid, still more than ten years into the project but it prevents cost over-run due to changes in standards (being a military project they find all sorts of other ways to over-run the cost!)

If you need to find out what amendments are applicable you need to find out what is calling up the standard (contract, national regulation, etc.) and see what is said about what version of the standard is to be used and at what stage the changes are frozen.

If this is a common problem it may be worth getting involved with the committee that updates the standard so that you are aware of what changes are coming through ahead of time (and may even be able to influence the changes).

Alasdair