Ask HN: What tools do you use for workload planning?

Essentially I want a tool as described in this blog post: http://justindavis.co/2015/07/29/capacity-forecasting-for-freelancers/

I need something to manage the capacity I have from contractors and employees and the workload I had and I will have across projects. Something to manage my projects, not in a detailed way, but from a time budgeting standpoint.

I cannot be the only person with many medium sized projects that works with a network and has a need for a tool like this. How do you solve this issue?