Add a cleaning crew to a Bikaner solar portfolio?
Before the decision
Output drops cluster around dust events, when multiple sites request crews together. The asset manager knows how often the panels were cleaned, but contract invoices do not show the generation gained after each visit. Site schedules vary with dust and access.
The problem
Should the team choose Own crew or Vendor callouts for the next 12 months?
Decision owner: The business unit lead.
A cleaning visit has value only when the recovered output exceeds service cost.
Option economics
Scroll the table to see all figures.
| Option | Volume (panel-service visits) | ₹ per unit | Fixed cost | Net contribution |
|---|---|---|---|---|
| Own crew | 56,000 | 98 | ₹44 lakh | ₹10.88 lakh |
| Vendor callouts | 51,000 | 65 | ₹25 lakh | ₹8.15 lakh |
Make the call
- Calculate net contribution for Own crew and Vendor callouts. Which assumption makes the comparison most fragile?
- If the leading option delivers 10% fewer panel-service visits, does your recommendation change?
- What evidence would you ask for before the team makes an irreversible commitment?
Reveal the worked solution
Start by validating Own crew. It contributes ₹10.88 lakh after fixed costs and leads by ₹2.73 lakh. Treat that gap as the amount of unmodelled cost or lost contribution the option can absorb before the ranking reverses.
- Frame the decision
Check the bottleneck at the busiest point in the operating cycle. An annual forecast can fit on paper while a peak week still breaks the service promise.
- Calculate both options
Own crew: 56,000 panel-service visits × ₹98 less ₹44 lakh in fixed costs gives ₹10.88 lakh. Vendor callouts: 51,000 panel-service visits × ₹65 less ₹25 lakh in fixed costs gives ₹8.15 lakh.
- Stress-test the forecast
Own crew leads by ₹2.73 lakh in the base case. If Own crew delivers 10% fewer panel-service visits (50,400) at the same margin and fixed cost, it contributes ₹5.39 lakh. Holding the other option constant, the stressed result falls behind. This isolates volume risk. Check whether both options would respond to the same change in demand.
- Set a decision threshold
Holding the other option’s result fixed, Own crew needs at least 53,215 panel-service visits to match or beat it under the model. Compare weather-adjusted generation around actual cleaning dates.
A cleaning visit has value only when the recovered output exceeds service cost. Compare the cost of a limited test with the loss the business would face if the full commitment failed. Ask the team to agree the decision criterion before collecting more evidence.
What if the whole market moves?
The worked solution tests a change to one option at a time. Here, both options gain or lose the same percentage of volume. Unit contribution and fixed costs stay constant.
| Volume scenario | Own crew | Vendor callouts | Higher contribution |
|---|---|---|---|
| Both lose 10% of volume | ₹5.39 lakh | ₹4.84 lakh | Own crew |
| Base assumptions | ₹10.88 lakh | ₹8.15 lakh | Own crew |
| Both gain 10% of volume | ₹16.37 lakh | ₹11.47 lakh | Own crew |
Explain which option you would take forward. Check whether capacity, price or customer mix would also change as the market moves.