The Workload feature (requires Business) in Asana helps you to visualise your teams current workload and capacity to take on more work. But you have to be careful. It's easy to set your team up for failure if you overestimate their available hours.
Here's a short interview with one of my clients, Patrick, who explains how he calculated everyone's available capacity by subtracting time for admin work and tasks he knows his team has to do each week. This left him with a more realistic idea of how much ‘actual' work people could handle. Patrick even adjusts his team's capacity every few months during the year as their workload and capacity change based on their busy seasons.
If you need help with Asana, optimising your account, improving team adoption or automating your processes, then check out my Master Asana program.