|The US Air Force maintains technical order warehouses at maintenance
depots throughout the United States. These warehouses contain the
maintenance and repair manuals for aircraft, ground support equipment,
and other vehicles in use on a long term basis.
An existing application had been written in Foxpro 2.6 for Windows
and SQL-Server 6.5 on NT Server. This system had been in use since
1995 operating on 486 based workstations and a 120Mhz, 64Mb(RAM)
server. The performance of this system was sufficiently constrained
that it had been necessary to divide the day into two activity
phases, because certain processing functions were so slow that other
operations were brought to a standstill.
The three primary issues confronting the users were the speed of the
system, bugs, and Y2K compliance. The system had been maintained by
a number of programmers over time, and as a result it generated
error conditions that users had to work around. Users typically spent
several minutes per order simply clicking through error message boxes.
Label printing was sufficiently clumsy that large label print runs had
to be restarted from scratch if some fault developed during the print
The solution evident to us was to rewrite the system in Visual
Basic, since this was a full 32-bit system and would make better
use of the 486 processors. After two months of development, we
invited the warehouse people over for a demo. The performance results
were a disappointment.
Placing more RAM in the existing server improved speed, although
not by much. We estimated at that point that more appropriate
processing hardware would consist of a server with at least 800
Mips effective processing power and enough RAM to contain the
entire database in memory. We configured and installed a Dell 6300
with dual 400 Mhz processors, 512Mb of RAM, and a five drive RAID.
This solution improved performance markedly and the operational
bottlenecks were largely eliminated.
We continued development on the Visual Basic system, first because
the Foxpro database in use was no longer supported by Microsoft, and
second because there were changing requirements elsewhere in the
organization that would have to be addressed. The workstations, in the
meantime, were replaced with Pentiums in order to deal with
networking performance and Y2K issues.
The system that we implemented was interoperable with the Foxpro
system (since both used SQL-Server), so there was no parallel
operations. As we brought on new functionality, the older programs
simply fell into disuse.
Kelly AFB was the original user of this system, however Kelly has
closed. This system is now in use at Warner/Robins, Tinker, and
This work was done by one of us as an employee of Datavise Engineering
Services. Resource Logic, Inc. was not and is not a contractor or
subcontractor to the US Air Force.