| Retail location rent |
Fixed |
Include $3,500 per month in base overhead from Month 1 through Month 60. |
Allocating rent per repair and making break-even look better at low volume. |
| Utilities |
Fixed |
Include $600 per month in fixed overhead within the normal shop planning range. |
Treating the full utility bill as sales-linked when the model lists it as monthly overhead. |
| Business insurance |
Fixed |
Include $450 per month as recurring overhead before calculating required contribution. |
Leaving insurance below the line and understating the monthly break-even hurdle. |
| Software subscriptions |
Fixed |
Include $300 per month for operating systems used to run repairs and administration. |
Moving subscriptions into variable expense even though they do not rise per repair ticket. |
| Parts & refurbishment costs |
Variable |
Reduce contribution margin by 20.0% of revenue in the first year, falling to 16.0% by the fifth year. |
Treating parts, rework, and refurbishment spend as overhead instead of margin reducers. |
| Payment processing fees |
Variable |
Reduce contribution margin by 2.5% of revenue in each forecast year. |
Ignoring card fees and overstating cash earned from each repair or device sale. |
| Fleet operating costs |
Semi-variable |
Model as usage-linked delivery and on-site repair expense at 3.0% of revenue in the first year, falling to 2.2% by the fifth year. |
Putting all vehicle activity in fixed overhead and missing the cost of mobile jobs. |
| Repair Technician payroll |
Semi-fixed |
Add capacity in steps: $45,000 annual salary starts in Month 13, then rises with FTE growth through the fifth year. |
Smoothing technician pay across every repair as if it moved perfectly with each ticket. |