Workshop
General Information 
The workshop has 50 units of space. Each unit can accomodate one working engineer, although each manufacturing project requires workshop space as well.
Workshop = Manufacturing = Money. Never have idle engineers, have them make something (anything) so you can sell it, even if you don't need it. Just be careful of using raw alien materials - Elerium-115, for example, is too precious to convert into cash.
The Laser Cannon is the most profitable project you can mass produce. If you take the cost of materials (Alien Alloys) into account, the Fusion Ball Launcher is about 25% less profitable. See Manufacturing Profitability for details.
Statistics
Construction Time: 32 days
Construction Cost: $800,000
Maintenance Cost: $35,000/month (see Maintenance costs)