What are the two biggest shortcomings of Gantt charts?

1. A Gantt chart shows scheduled against actual time for each listed activity. 2. Its first weakness is that it is static, so it does not adapt as the project changes. 3. Its second weakness is that it fails to show how the tasks are related to one another. 4. Without those relationships a manager cannot tell which delay matters and which does not. 5. Both problems can be solved by using the critical path method or PERT instead. 6. Cost and software are not the issue, and Gantt charts are used in services as readily as in factories, so options A and B miss the real limitation. _Source: OpenStax Introduction to Business (CC BY 4.0), Ch 10 "Achieving World-Class Operations Management", section Tracking Progress with Gantt Charts_