In the next few months Digital Equipment Corporation's program of guaranteeing 96-99% uptime on certain systems is likely to be followed by other minicomputer manufacturers according to trade sources. Welcome as such guarantees may be, they are unlikely to be of particular significance in the library automation market as central processing unit (CPU) failure accounts for only a small proportion of the problems libraries experience with their systems. As outlined in the first issue of LSN, peripheral devices tong to be less reliable.
The review of a number of recent specifications for library automated systems reveals that reliability levels of 98% for the first three years of installation are now commonly accepted. However, this does not relieve a library of the need to define reliability requirements when specifying a system, monitoring system performance to insure that the requirements are met, and seeking redress when performance falls below the contracted levels.
In contracting with the turnkey market for an integrated automated system comprising circulation control and related functions such as acquisitions, patron access catalog, and serials control, the following requirements are common, although the reliability percentage is subject to vigorous negotiation:
- The automated system shall be 98% reliable for the first three years after initial installation and 97% from the beginning of the fourth year through the end of the fifth year after initial installation.
- Reliability shall be determined by deducting down time from the total number of hours the library is in operation.
- Downtime shall be that period of time when it is not possible to perform scheduled activities due to equipment or software malfunction or when the system is released to the vendor for remedial maintenance.
- Downtime shall be calculated to the nearest one-tenth hour and calculated as a percentage of the library's total operating hours. For example, if the library is in operation a total of 400 hours monthly, seventeen hours of downtime of the total system or the equivalent combination of individual components or features would reduce the reliability level to 98% for the month.
- The following table of coefficients shall be used to compute downtime:
- Errors which do not affect current system performance shall not be counted until the 50th operating hour after report to the vendor. At that time they shall be calculated at a coefficient of .10 from the 50th hour.
| Loss of charge-discharge capability | 1.00 |
| Loss of hold feature | 1.00 |
| Loss of patron file inquiry | 1.00 |
| Loss of item file inquiry | 1.00 |
| Loss of file-update online | 1.00 |
| Loss of report printing for more than six operating hours | .25 |
| Other software problems which affect system performance | .10 |
| Loss of terminal | .10 |
| Loss of single disk, if system is operating | .50 |
| Loss of tape drive | .25 |
| Loss of console printer | .25 |
| And, in addition, as the related functions are installed: | |
| Loss of acquisitions function | 1.00 |
| Loss of patron access catalog | 1.50 |
| Loss of serial control function | 1.00 |
Failure of the automated system to perform at the contracted levels of reliability frequently results in a library withholding 10% of the monthly maintenance fee for each 1% that the system falls below the contracted reliability level. Although such expectations and penalties may be spelled out in the contract, many libraries are failing to benefit from their inclusion because they neglect to log and record system failures.
