Most corporations relying on their network for their business find that it is necessary to upgrade the software powering their network gear (routers, switches, etc.) on a regular basis. The reasons for this vary from out-of-compliance software, to deploying new features, to standardizing on a corporate version on all routers/switches. Such a network-wide upgrade, on a live network, poses risks and comes at a cost. One of the biggest problems with upgrades is that the risk/reward balance is asymmetric; if it goes well, then the rewards are relatively unnoticeable; if it doesn’t, the penalties can be huge. The rewards can be exemplified as the resolution of an issue or the ability to deploy a new network service such as VoIP. The penalties will be much more spectacular; for example, the network might go down, with devastating consequences to the corporation, and the work to resolve and restore the network can be extremely costly—not least to the future career of the decision maker. To make an upgrade successful and to avoid adverse impacts, the upgrade must be carefully planned and executed. This requires a Method of Procedure (MOP) created with a “Plan B” for backing out the changes, with thorough testing of all steps on the proper equipment as essential elements.