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 Deploying a LIMS on a central database with users in different parts of the World introduces an issue regarding timestamps. The issue is that different users are in different time zones than the database where the database time is not a meaningful basis for recording activities. For example, if the database is in a time zone that is one hour ahead of where the users are located and a user logs a sample, he would be confused if the login timestamp was one hour in the future. Obviously, the problem is more severe the larger the difference between the user and the database server.
LabWare LIMS solves this problem in two different ways; one for client/server users, and the other for Citrix users. Client/Server architectures have the code running in a different location than the database server, so the local timestamps are pertinent. However, different PC's may have their clocks set differently which could introduce an inconsistency of timestamps. In this configuration, LabWare LIMS synchronizes the clock on each PC with the database server time. Users in different time zones have different offsets so their times are consistent, but different from users in other time zones.
With Citrix, the problem is different because the processing is all taking place on central servers. The time on each users' PC does not matter because the application is not generating timestamps on the users' PC. With Citrix a different scheme is employed. Under Citrix the time offset of users is determined relative to each users offset from GMT (Greenwich Mean Time). Citrix can determine the offset based on the Windows client regional time settings. LabWare LIMS uses this information to correct the timestamps generated by the server to the actual times where the user is located.
Consistency of timestamps is important for Good Laboratory Practices (GLP) where demonstrating the sequence of operations is required. LabWare LIMS maintains consistency in both client/server and Citrix deployment architectures. |