The problem originated with the desire to save storage space both disk and RAM in early computers which by today s standards had minuscule capacities. An early 1970 s LIS would have had less than 100MB of disk and under 100K of RAM less than one percent of current capacities. Small storage devices required programmers to eliminate every unnecessary bit and byte in their designs. Since a time and date stamp may be associated with numerous activities in a single laboratory test e.g. order time, collection time, result time, etc. The problem was not limited to dates.
Laboratories are fortunate in the way software is developed, sold and supported.
While many packages become obsolete in a few years, the tendency in the LIS field is to provide regular updates so that systems five or more years old might still be able to run the latest version of the software. Since the Year 2000 problem is strictly a matter of upgrading software to account for dates beyond 1999, the updating policy of LIS vendors can naturally take this into account. This is not much different than any other mandatory change you must make e.g. to respond to regulatory requirements when the vendor is not willing to make the needed software modifications. Outside the cozy realm of packaged, turnkey systems, the problems are much more severe and involve major computer systems developed for corporations and government agencies over a period of 20-30 years. 70 s are still in use.