Over the years a number of US MIL standards have been replaced by MIL guidance handbooks (for instance MIL-STD-454 has been replaced by MIL-HDBK-454). The MIL standards were full of "shalls" whereas the MIL-handbooks are full of "shoulds". This shift is rather unfortunate from a contractual point of view since MIL handbook 454, for instance, states that it cannot be used to place mandatory requirements and the designer need not comply with the guidance provided. This seems to be particularly unfortunate since MIL-STD-454 (Requirement 1) was probably the most important souce of MIL personnel safety requirements. The specifications for numerous US military items, however, still refer to this guidance handbook as if it is a repository of mandatory requirements. In reality this seems to me to leave the issue of what the equipment design actually complies with as completely undefined.
I would like to hear any opinions as to how MIL-HDBK 454 is perceived from a contractual standpoint. How much freedom do US military equipment designers out there feel they actually have, given the complete lack of "shalls"? Dave Palmer, UK
