One of the programs in which macros are commonly used is in Microsoft Excel. In MS Excel, users create macros using the Record Macro tool and are able to drastically reduce the time spent on menial repetitive tasks and significantly improve their productivity.
For example, a macro can be used to collate data from 1000+ Excel files into a single report in about 5~15 minutes. On the other hand, doing the same job manually would take almost an entire day if not more. Further, with increased repetitiveness of a task, people enter a state of complacency and boredom which results in sub-standard output of work.
However, the accuracy of a macro being a software program will be the same irrespective of whether it is processing 1 file or 10,000 files and is dependant only on how well it is written.
Due to lack of knowledge/awareness of the presence of a similar macro functionality in Microsoft Project, project managers who use MS Project sometimes fail to make use of this feature.
For an introduction to MS Project, please read this step-by-step tutorial on how to get started with Microsoft Project.