Building a simple financial model to support growth

I run a small joinery manufacturing business and I’m looking for help building a simple financial model to support growth.

I want to understand:

• My true monthly break-even point
• How much turnover is required to safely take on additional staff
• What level of profit I should be targeting per job
• Cashflow requirements to avoid getting into trouble

Current position:

• Two members of staff
• Small workshop producing kitchens, wardrobes and cabinetry
• Looking to scale in a controlled way