custom reporting waiting delays improvement

we developed custom reports which all of our teams have to run for every client we service from within a custom report company everyone has access to, most of our team members have experienced issues running the reports - an error message comes up constantly stating "You have reached the maximum number of tasks running at once. Please try again later".

The team are having to nearly wait for 10-15 mins before they can run the reports, as you can imagine this is delaying processing and causing frustration. We are looking to see if there are any options available to improve this, would it cause less issues / delays if the custom reports were built into each company shell rather than being run from the same company shell or would it still have the same delays due to this being a custom report? Is there anyway the limit for max users / system tasks running can be increased so this error is less frequent, and the reports are produced quicker?