I have a fixed-sized team (with fixed-hours) and products, more than the team can handle. At any given time, while my resources are working on one product, requests keep flowing in about work on other products--most of them with conflicting timelines--and I find it difficult to predict when we can take up the new task based on resource availability.
I want to be able to answer the question "Which resource is working on what product release till what time?" at a glance. How can I do that?
Utilization is less important than capacity. I would generally recommend measuring team capacity to see how soon a task can be added, rather than trying to determine the utilization of individual team members.
If you have a large number of demand-queued tasks, you may want to consider Kanban as a both a project methodology and as an estimating technique. Kanban is a great system when you need to manage (and estimate) based on work-in-progress constraints.
As a gross simplification, if you have 6 members on your team, and a work-in-progress limit of 12, you might use a trailing average of past performance to determine that your team can generally handle 36 requests in a week.
By prioritizing backlog items or measuring the total depth of your request backlog, you can estimate when task X can be pulled into the work queue, or how long it will take to "empty the bucket" of all pending tasks. Plus, the kanban itself (meaning the physical board) is a great at-a-glance visual tool.
As a previous responder has said, your focus should be on capacity. If you haven't read "The Goal" by Eliyahu Goldratt, you really ought to. In the book, we learn about the Theory of Constraints, which posits that an entire production chain can only move as quickly as the slowest element of the chain.
The book uses a factory as a framework for the Theory of Constraints, but service organizations can learn equally well.
What's important we do is measure capacity by person. Can this person design 10 graphics in a day or can they write three blog posts in a week? From there, you can identify bottlenecks and increase capacity by either educating your employees, creating process efficiencies, or hiring.
Measuring throughput can be difficult, but organization-level task management software like Asana or Basecamp allow you to see what individual capacity is.
