Siyakhula Solar is a Cape Town-based installer of commercial rooftop solar systems for warehouses and retail centres. The company depends on inverter and battery suppliers because their equipment and technical support affect whether a site can be switched on and handed over on time. After installation, Siyakhula must commission the system, which involves testing and confirming that the inverters, batteries, protection devices, and monitoring software are configured correctly, operate safely, and deliver the expected output before the customer accepts the project. When supplier documentation is unclear, settings are wrong, or technical support is slow, Siyakhula experiences delays at handover, extra site visits, and warranty call-backs. The CEO wants supplier relationships to change in practical ways, not just in wording. Which set of relationship characteristics reflects a collaborative buyer–seller relationship in this situation?