Hi @Mark_Openshaw and thanks @Bastien_Siebman,
I agree with Bastien; the upcoming Workload feature could help if you’re considering or on the Business Tier. You’d need to assign to the resource as Bastien writes. But you don’t need to pay for seats if you use a single gmail account like mycompany@gmail.com because they let you make unlimited mycompany+scissorlift@gmail.com, etc. for each resource for free, and none of those count to your Asana seats because they’re Guests. But you would have to use multiple tasks for the assignment (e.g., Task Actions > Create Follow-up Task) or subtasks of the one task in order to assign these additional resources since one task can only be assigned to one person/resource.
Another approach that doesn’t require either Business or the gmail stuff is to use Tags like scissor lift. If you also define one single tag named resource then you can always click that tag to see a list of all tasks that possess that tag resource (and in addition the specific tag like scissor lift) and then sort that list by date which would enable you to see the scheduling of all your resources by date so you could answer your question. That view can also be seen as a Calendar instead of a list if that’s helpful too.
Usually custom fields, a Premium feature, are recommended, but in this case I think tags is better because 1) there’s no multi-select custom field (yet) so you wouldn’t want to make a Resource custom field because it could only have one value at a time, and 2) tags are easier to use across multiple projects, in case that’s an issue for you.
Hope one of those works!
Larry