GAUDI-Architecture design document

98-064 This document is the result of the architecture design phase for the LHCb event data processing applications project. The architecture of the LHCb software system includes its logical and physical structure which has been forged by all the strategic and tactical decisions applied during development. The strategic decisions should be made explicitly with the considerations for the trade-off of each alternative. The other purpose of this document is that it serves as the main material for the scheduled architecture review that will take place in the next weeks. The architecture review will allow us to identify what are the weaknesses or strengths of the proposed architecture as well as we hope to obtain a list of suggested changes to improve it. All that well before the system is being realized in code. It is in our interest to identify the possible problems at the architecture design phase of the software project before much of the software is implemented. Strategic decisions must be cross checked carefully with the experts (the reviewers) because they are essential for the system which is being developed, specially if the system needs to be operational for very long time scales.