What constitutes excess schedule lag?

Some people say anything over 0 is too much, others say a week, but why not 60 days?

http://www.eaglecoatings.net/content/liningkote6000.htm

As you can see the waiting period represented by lag is not a fixed amount, in the case of the epoxy finish on the reference curing time is 60 days. What is important is that your software provides transparency, that it provides for you to explain the lag, that it is not a number taken from the air. It shall also allow you to filter for lag amount as unusually large amount of lag should be validated which is different to forbidden.

Some say lag can be modeled with an activity, but it is not the same, otherwise we would schedule only with lag and would not use activities. They are modeled differently, they are not the same. Very frequently use of lag is more efficient, just keep it transparent.

Lag is part of what defines a link, links are what differentiates a simple Bar Chart with no logic from a CPM, unfortunately some developers do not provide the user the most basic table to see the links definition. What makes it so incredible is that the information somehow is there but you are not given the most basic view.

Best regards,

Rafael