The English National Health Service Requirement
			for Application Conformance Testing

	The open systems movement has been driven largely by market
	requirement for greater choice.  However, there are a large
	number of political and technical problems that still need
	addressing.  This short paper will outline some of those
	problems related to open applications, with particular reference
	to POSIX, from the English NHS point of view.

	When a standard is adopted it should be done primarily for sound
	business reasons.  There needs to be a demonstrable benefit.
	The English NHS believes that there is a business case for
	adopting the POSIX standard (investment protection in hardware
	and operating systems, market choice, protection of staff
	expertise).  These benefits can be realised because the majority
	of operating systems now conform to POSIX.1 and POSIX.2 (or will
	do so).  The vendors of operating systems conform because they
	have been motivated by market pressure.  First and third party
	testing has allowed operating system vendors to gain competitive
	advantage by demonstrating conformance and has given purchasers
	confidence to buy operating systems that conform.

	Unfortunately there is little evidence that application
	developers are writing to POSIX standards.  Unless they do so
	the whole exercise will have been a waste of effort.  Until
	application developers start to actively make use of POSIX
	standards, and tell customers about it, the primary goal in
	developing POSIX will no be reached.  It is quite likely, if
	application developers do not start to use the standard and
	advertise that fact, that operating system vendors will cease to
	support it.

	The English NHS mandates POSIX in all relevant purchases above
	GBP 5000 (with appropriate derogations).  This level of
	commitment requires support in training and guidance for
	purchasers, technical expert help, procurement help, and
	maintenance and development of POSIX standards requirements.
	Without applications to support POSIX there is little business
	reason to continue to mandate its presence, especially when the
	cost of mandating it is taken into consideration.

	Two further problems complicate the situation.	(i) Potential
	purchasers of open applications can not be expected to have the
	expertise needed to accurately assess the conformance (or lack
	of it) in an application.  (ii) As there is no application
	testing available, public bodies may derogate from the EC
	Standards Decision where applications are of concern.


	Application conformance testing is necessary in order to
	encourage purchasers to require POSIX conformant applications.
	Application conformance testing gives purchasers the ability to
	accurately assess the conformance claims of a vendor.
	Application testing may be necessary to persuade application
	developers to adopt the standard.  The situation for conforming
	applications is the reverse of that for platforms, ie very
	little support for the standard.  For platforms there is
	adequate first and third party testing available, and support
	for the standard is almost universal.

	The POSIX standard is being developed "to support application
	portability at the source level" (1).  This support will not be
	achieved without application conformance testing.  There is an
	urgent requirement to develop application test benches for POSIX
	before users of the standard start to seriously question the
	worth of continuing to use it.


	Robert Smith
	NHS Information Management Centre

		(1)  Portable Operating System Interface (POSIX) - Part
		     1: System Application Program Interface (API) [C
		     language]	 ISO 9945-1.