The scope of CSI can include Service Practices Improvement – the warranty of the services – and Service Systems Improvement – the utility of the services.
Tipu talks a lot about Service Practices Improvement because that is generic to all organisations.
Tipu is equally useful for driving Service Systems Improvement, but the actual Mahi will be unique to your systems.
One last thought: Tipu isn't actually tied to CSI. Tipu could be used as a method of improving anything at all.