One of the most critical parts of the troubleshooting process is testing the solution. If the solution involves some type of major change or fundamental modification to the network infrastructure or design, the recommendation is to test the solution in an isolated prototype environment first.
If possible, as a best-case scenario, you should have an exact mirror of the network topology, or at least try to get as close to this as possible. This could mean trying to create a subset of the network infrastructure on which the solution can be tested. For example, the solution might involve applying some type of service pack or software upgrade on different devices, and this should be carefully tested in an isolated environment before launching such a drastic change into production.
During the implementation and testing phase, network technicians usually create scripts in order to execute multiple tasks at the same time to save time. Following this advice, you should prepare a detailed implementation plan and testing procedure before starting the actual work to minimize possible problems that might occur. In addition, you should have technicians with higher seniority available if things get out of control.
From a testing standpoint, solutions should be tested based on their complexity, starting with the simple ones first, in order to achieve maximum efficiency.