Background and Objectives: An implementation of NONMEM as the standard software for modeling in a global pharmaceutical company should consider the following requirements to be successful: a) multi-user and multi-site access, b) large, scalable and cost efficient (distributed) computational resources, c) regulatory and company rule compliant file handling, d) user-friendliness. Our objective was to build an interface/environment that fulfils the above mentioned requirements.

Methods: Perl was used to develop the PROPHET environment that technically bases on the grid architecture and offers the possibility to access globally distributed computational resources. Dedicated standard PCs using Linux as operation system were used as calculation nodes, focusing the multi-user access to a front-end server that mainly acts as data server. To ensure resource efficiency in the given setup a queue with a priority system was implemented on the front-end server. The system can be easily extended by addition of further nodes.
Calculation results are automatically transferred from the nodes to the front-end server and stored in project related user directories according to their file type. To ensure data integrity a file protection system was implemented that is activated at submission of a run. The archive file (containing all information and output of a run) and an additional audit trail file are created and stored in a dedicated result area giving only read-access to the submitting user.
User interaction with the queue allows submitting, removing and delaying of own runs as well as viewing actual iterations of calculating runs. To enhance user-friendliness and automation configurable tags can be included in the model control stream, triggering different actions after calculation (e.g. S-Plus goodness-of-fit plots or summary report generation). A Samba share for Windows file access and a web interface allowing communication with the respective queue were set up to make working with PROPHET easier for users unfamiliar with Unix/Linux. 

Results and Conclusion: The PROPHET environment has proven to be very stable, resource efficient, easy to administer and to extend global system for the use of NONMEM. The user-friendliness resulted in high acceptance by the users. Using only standard hardware components and standard software allows being prepared to upcoming challenges and expansions. A single user version with reduced functionality (open source) can be downloaded free of charge at: http://www.pkpd-expertentreffen.de/