There are lots of interestingly different ideas on how much 'cost' there is to this coordination. Ranging from it's a very low overhead, to it requires a full time manager who is the highest paid person on the team. Often these drastically different opinions are held on the same teams by the same people.
What I want to explore today however is what does the actual coordination looks like and what it would mean to get it right.
To start off with, there are a few types of coordination:
Multi-functional coordination
If someone is building the database and someone is building the UI those things need to talk to each other; usually through a middleware build by a third person. If they don't line up the costs are large indeed, ranging from "we need to redo this" to the far worse "Let's ship the wrong thing".
The coordination includes:
- knowing what each piece looks like
- which functionality goes where
- how to connect them
If you know the answers to all of this, then I believe you can make a fairly good assembly line fashion process.
However, I would like to state categorically
"If you have not yet built it, you don't know everything involved"
or as the great Woody Zuill said
"It's in the doing of the work that we discover the work that needs to be done"
And I don't mean done 'something like it'. If you've ever done a remodel on your house you will notice the estimates don't match the end result. It's not that this is the first remodel the contractor has ever done. Each situation has it own unique unknown unknowns.
Unfortunately, in software we are always doing something new because duplication is a copy and paste away.
Coordination of these types of tasks is expensive. You need an level of detail and level of oversight that is time consuming to obtain. If you don't get it right there is a lot of waste in the process that is silent.
Multi-person coordination
Even if you have people with the exact same skill set you will often have them working separately in an effort to maximize throughput. Here the coordination is in reducing duplication and keeping the code united. You don't want different people creating the same things or worst the same things in a different way where it's hard to realize they are even the same things. Ideally you want everyone producing unique work in the best possible way.
Perfect coordination
I think perfect coordination is easiest to picture in a single entity. This entity is aware of the details and the larger picture. It has the skill sets for all aspects of the code. It incorporates new knowledge and processes the moment it learns them. It has a memory of the previous work and knows when it should reuse pieces. It has high self awareness and doesn't have to spend a lot of time in meeting talking about work.
For many small projects this entity has been a single person.
I hypothesise that it is also the reason a Mob can be effective.