Have something on the go
Definition 1 of 2
Pro Tip 1/3Simultaneous Projects
Used when someone is actively involved in multiple projects at once, not just planning them. 
She's renovating her house and starting a business; she's got a lot on the go.
Pro Tip 2/3Busy Schedule
Indicates a very active and potentially stressful schedule due to many ongoing activities. 
With three kids and a full-time job, Mark has a lot on the go.
Pro Tip 3/3Active Involvement
Implies direct and active involvement in activities rather than delegating or observing. 
Jane not only runs two shops but also volunteers at the shelter; she loves having things on the go.