Reliable suppliers are essential to the success of every solar installation business. Even the most experienced installer can face project delays, unhappy customers, and unexpected costs if equipment arrives late, damaged, or with poor technical support.
A Service Level Agreement (SLA) helps installers and suppliers set clear expectations. Instead of relying on promises or assumptions, an SLA measures supplier performance using agreed Key Performance Indicators (KPIs). This creates accountability, strengthens business relationships, and improves project delivery.
Why Supplier SLAs Matter
Many disputes between installers and suppliers are caused by unclear expectations rather than poor intentions. Questions such as "What is an acceptable delivery time?" or "How quickly should a faulty inverter be replaced?" often have no agreed answer.
A well-written SLA provides measurable standards that both parties understand before problems occur. It also gives installers confidence that suppliers will consistently meet agreed performance levels.
Key Benefits:
- → Better project planning
- → Fewer installation delays
- → Improved customer satisfaction
- → Faster warranty handling
- → Stronger supplier relationships
- → Better procurement decisions
For South African solar businesses operating in a competitive market, supplier performance can directly affect profitability.
KPI Selection – What Really Predicts Installer Pain
Not every performance metric is useful. Focus on KPIs that have the greatest impact on installation schedules and customer satisfaction.
On-Time In-Full (OTIF)
OTIF measures whether orders arrive:
- ✓ On the agreed delivery date
- ✓ With the correct quantities
- ✓ Without missing items
Late or incomplete deliveries often delay installations and increase labour costs.
Typical Target: 95–98% OTIF performance
💡 Tracking OTIF over several months quickly identifies reliable suppliers.
Lead Time Performance
Lead time measures the number of working days between placing an order and receiving the equipment. Rather than using estimated delivery dates, measure actual performance against agreed lead times.
Example Targets:
- • Standard stock items: 2–5 working days
- • Special-order items: agreed case-by-case
💡 Consistent lead times improve installation scheduling.
Dead on Arrival (DOA) Rate
A DOA product is defective before installation or fails immediately after commissioning.
High DOA rates lead to:
- ⚠ Additional labour
- ⚠ Return visits
- ⚠ Customer complaints
- ⚠ Delayed project completion
An SLA should define:
- • What qualifies as DOA
- • Inspection procedures
- • Reporting deadlines
- • Replacement process
Industry Standard: Less than 1% DOA rate
RMA Cycle Time
Return Merchandise Authorisation (RMA) cycle time measures how quickly warranty claims are completed.
The RMA process includes:
- 1. Fault reporting
- 2. Supplier assessment
- 3. Approval
- 4. Replacement or repair
Long RMA times increase installer costs and frustrate customers.
Practical KPI Targets:
- • Initial response: within 1 business day
- • Replacement approval: within 5 working days
- • Complete resolution: agreed timeframe
Technical Support Response Time
Installers often require immediate technical assistance during commissioning.
Key Metrics to Measure:
- • First response time
- • Resolution time
- • Escalation procedures
Example Targets:
- • Phone support during business hours
- • Email response within 4 working hours
- • Critical issues prioritised immediately
💡 Fast support reduces downtime and repeat site visits.
SLA Structure – Targets, Exclusions & Remedies
A good SLA is practical, measurable, and realistic.
Define Performance Targets
Each KPI should include:
- • Performance measure
- • Target value
- • Measurement period
- • Reporting method
| KPI | Target |
|---|---|
| OTIF | 97% |
| DOA Rate | Less than 1% |
| Technical Response | Within 4 hours |
| Warranty Response | Within 1 business day |
| RMA Completion | Within agreed timeframe |
⚠️ Avoid vague wording such as "reasonable" or "as soon as possible."
Include Exclusions
Certain events are outside the supplier's control. Clearly defining exclusions prevents unnecessary disputes.
Common Exclusions:
- • Port delays
- • Customs inspections
- • National transport disruptions
- • Force majeure
- • Manufacturer production shortages
Specify Responsibilities
Both parties should understand their obligations.
Supplier Responsibilities:
- • Accurate deliveries
- • Product quality
- • Warranty handling
- • Technical support
- • Regular performance reporting
Installer Responsibilities:
- • Accurate purchase orders
- • Proper storage
- • Timely inspection
- • Prompt defect reporting
- • Correct installation practices
💡 Shared responsibilities improve accountability.
Include Remedies for Non-Performance
If KPIs are repeatedly missed, the SLA should explain what happens next. The objective should be continuous improvement rather than punishment.
Possible Remedies:
- → Corrective action plans
- → Management review meetings
- → Priority support
- → Improved delivery scheduling
- → Temporary stock allocation
- → Contract review
Evidence & Reporting – Tracking Without Overload
Performance management should not create unnecessary paperwork. Most installers already have sufficient information in their purchasing systems.
Key Records to Maintain:
- ✓ Purchase orders
- ✓ Delivery notes
- ✓ Courier tracking
- ✓ Invoice dates
- ✓ Warranty claims
- ✓ Technical support emails
These documents provide objective evidence when reviewing supplier performance.
Create a Simple Supplier Scorecard
Rather than collecting dozens of statistics, monitor a few important KPIs every month. Colour-coded dashboards make trends easy to identify.
Monthly Scorecard Template:
- 📊 OTIF percentage
- ⏱️ Average lead time
- ⚡ DOA rate
- 📋 Number of warranty claims
- 🔧 Average RMA completion time
- 📞 Support response time
- ⭐ Overall satisfaction rating
Hold Regular Supplier Reviews
Quarterly supplier meetings allow both parties to align on performance and improve partnership. Regular communication often prevents small problems from becoming major disputes.
Quarterly Meeting Agenda:
- 1. Review KPI results and trends
- 2. Discuss recurring issues
- 3. Identify improvement opportunities
- 4. Forecast future demand
- 5. Plan stock requirements
Keep Accurate Records
Evidence is particularly important during warranty discussions. Good documentation protects both installers and suppliers.
Documentation to Maintain:
- 📸 Photos of damaged deliveries
- 🏷️ Serial numbers
- 📄 Commissioning reports
- 📝 Fault logs
- ✍️ Customer sign-off documents
- 💬 Email correspondence
Negotiation Tips – Volume for Performance
Installers often focus only on negotiating lower prices. However, reliable service can save more money than a small discount.
Use Purchasing Volume as Leverage
Suppliers may agree to stronger SLA commitments when installers provide:
- → Regular purchasing volumes
- → Annual forecasts
- → Preferred supplier status
- → Long-term business relationships
💡 Consistent customers often receive better service.
Prioritise Service Over Discounts
A supplier offering slightly higher prices but delivering consistently may reduce:
- ↓ Labour costs
- ↓ Return visits
- ↓ Customer complaints
- ↓ Installation delays
Total project cost is often lower despite higher product prices.
Review Performance Regularly
Business conditions change over time. Regular updates ensure the SLA remains practical.
Review SLAs annually or whenever:
- • New product ranges are introduced
- • Delivery regions expand
- • Sales volumes increase
- • Market conditions change
Align Quality Standards
Quality expectations should support recognised installation practices. Using industry guidance such as the PV GreenCard quality checklists helps installers maintain consistent standards while improving communication with suppliers.
Building Strong Supplier Partnerships
An SLA should strengthen cooperation rather than create conflict. When suppliers understand what installers measure, they can focus on improving the areas that matter most.
The best supplier relationships are built on:
- ★ Honest communication
- ★ Shared performance goals
- ★ Reliable reporting
- ★ Fair expectations
- ★ Continuous improvement
Conclusion
Supplier performance directly affects project profitability, customer satisfaction, and business reputation. Measuring service through clearly defined KPIs such as OTIF, lead times, DOA rates, RMA cycle times, and support response times allows installers to make informed procurement decisions.
A practical SLA, supported by simple reporting and regular performance reviews, creates accountability for both parties. Instead of debating whether service is "good" or "bad," installers and suppliers can rely on measurable results that support long-term success in South Africa's growing solar industry.
