Reynard said:
Wait, the real world never exceeds a budget? I think Traveller should reflect the real world with a roll whose effect level determines how, percentagewise, over budget a project goes. This needs to be rolled as a last step because you never hear what it will be until long after projects are underway and it's too late to halt.
I was going to say...
But yes, essentially you have three choices if you've clearly not got the budget to complete a piece of design work:
1) Reduce the scope (i.e. the capability of the finished design)
2) Extend the design period (allowing you to draw on the next budget cycle for the design activity)
3) Commit more money (over and above what you'd planned to spend on design in this budget cycle).
Most times, military programmes end up doing some combination of 1 and 2, although (1) is more normally invoked in the manufacturing stage by reducing the number ordered, rather than scaling down the capability requirements for each unit at design.
If you wanted to throw in some assumptions to make design more 'realistic', then yes, hard budget limits are one thing you could use.
Another is a requirement for some unused space - less relevant for the 3I, I guess, with it's glacially slow tech development, but most naval ships will be designed on the assumption that they'll undergo at least one major refit and upgrade programme during their service life, and hence the assumption that sensor fits will increase in size by a dTon or two each, that you'll end up carrying 10% more small craft and fighters (or fighters which are significantly larger), or that there may be a decision to convert some cargo space into additional magazine space (hence putting them next to one another would be good), etc, etc.