What is one of the limitations of the bar graph?

It can only shwo discrete (non-continuous) data

Answer:In any project, there are large numbers of activities which can be started with a certain degree of concurrency; the bar chart cannot indicate clearly the independencies among the various activities. This is a major limitation. The mere fact that two or more activities are scheduled for simultaneous overlapping times do not always make them related to interdependent or completely independent.