| Small Warehouse and Office Rent |
Fixed |
Include the $2,800 monthly rent in fixed overhead for the planning range. |
Pushing rent into each installation and overstating job-level margin pressure. |
| Insurance, Software, Utilities, Mobile Data, and Dues |
Fixed |
Combine the $450 insurance, $150 scheduling software, $300 utilities, $200 mobile data, and $100 dues as $1,200 monthly overhead. |
Letting small recurring bills sit outside break-even because each line feels minor. |
| Baseline Salaried Payroll |
Fixed |
Treat planned salaries as monthly overhead until staffing changes with capacity. |
Charging salaried payroll like hourly job labor and double-counting labor burden. |
| Safety Gate Wholesale Inventory |
Variable |
Reduce contribution margin by the Year 1 inventory load of 14% of revenue. |
Modeling gate inventory as overhead instead of a sale-linked material spend. |
| Installation Hardware and Mounting Kits |
Variable |
Reduce contribution margin by the Year 1 mounting kit load of 4% of revenue. |
Ignoring small parts and overstating profit on standard gate installations. |
| Vehicle Fuel and Maintenance |
Variable |
Apply the Year 1 6% rate against revenue; callbacks should also reduce contribution margin if they rise with jobs. |
Treating route costs as fixed even when more jobs mean more miles and return visits. |
| Paid Marketing |
Semi-variable |
Model the first-year $12,000 budget as planned spend, then test volume using the $65 customer acquisition cost. |
Using only the annual budget and missing how acquisition efficiency changes required sales. |
| Added Technician Staffing |
Semi-fixed |
Add new salary blocks when capacity steps up, such as more lead technicians or junior installation assistants in later years. |
Smoothing headcount into each job and missing the margin drop when a new hire starts. |