The Scripting Guide has several suggestions. Look under the heading administering scripts.
To quote:
! Nortel Networks recommends that you do not activate scripts during busy call center periods.
! Activation of scripts can cause the call center to go into default mode. This is because script activation has a high impact on the server and can cause Task Flow Execution to become too slow. Running reports can also cause the same problem. Task Flow Execution has enough time to process calls simultaneously with Script Activation based on the following conditions:
! the amount of real time available to Task Flow Execution when all other activity in the call center is taken into consideration
! the length and complexity of the script
! whether it is the Master script, as it then looks at all the scripts attached to it and their complexity
! Scripts that use a lot of resources, such as If-Then-Else statements, nested commands, skillsets, and so on, can take a long time to validate. This problem can also be caused by only validating a script, because this
validation also runs on the server. While delays are less likely to occur during validation than activation, it is still important to avoid validation during busy hours.
! To avoid having to reactivate the Master_Script when writing test scripts, keep a test CDN and a Test Primary Script activated at all times. Then, only edit and change the Test Primary Script, not the Master_Script. You can
also use other secondary test scripts. However, it is still advisable to make changes outside busy hours.