Sample Calculations: CDS versus LIMS

[shaun78]

I am looking to obtain other people's opinions about this. Mainly as a testing ground to find out if I am completely off base or not.

Anyway, the company I am currently working for seems to be getting ready to go down a very awkward path in my opinion. For our impurity methods we are going to have our CDS (Empower) do the integration and peak naming. The individual impurity percents will be pushed into or LIMS system (Labware) where total impurities, total unknown impurities, and total known impurities will be calculated.

Question: Is this a good or a bad idea to have calculations being performed in two different systems such that neither system ever has the complete set of data? I work in a FDA, cGMP, cGLP, et all environment.

It seems to me that the best practice here would be to handle all the calculations in the CDS and then push everything in it's completed and reported state to the LIMS system. But, there is more than one way to skin a cat...

[Johnny Rod]

It partly depends if either system is capable of producing the sets of values you need for your reporting. To be honest though, that aside, I don't see the problem with the approach. It simplifies (and reduces) the data being passed from one system to another as to calulate the amounts/percentages for each peak there are a number of pieces of data. To work out the amounts first then pass them across to LIMS woudl make some sense, also when you want to change the way it's reported, you have no changes to make in the CDS, it's all done in LIMS.

[MakoBrad]

we recently installed LIMS and went the route of doing the calculation in the CDS and then hand entering the final data (out beyond the specification limit). LIMS then rounded the calculated data to the spec level......now that I type this I realize we are double rounding.

We do not have instrument integration at this time. The rationale for doing it this way was that the CDS value was allready validated so there would be no need to validate the calcs in LIMS.

I would love to hear others opinios pro/cons on this matter

[DR]

Think of every different system that does calculations as a loaded gun.
How many of them do you want pointed at your foot?

[shaun78]

In light of DR's response and to come full circle on this, I've managed to push back hard enough so that the calculations are being performed in the CDS.

I don't like the approach of LIMS handling data calculations for many many reasons ... mainly it is another system for someone else to audit.

Instead, LIMS is now pulling data from the CDS and generating a C of A for the client.