Architecture of the ITIL SVS specifically enables flexibility and discourages siloed working. This is because the service value chain and practices do not form a fixed, rigid structure, but rather they can be combined in multiple value streams to address the needs of the organization in a variety of scenarios, with open flow of communication across the many interfaces.
Reference: https://www.bmc.com/blogs/itil-service-value-system/

There are many ways in which practices and services can be optimized. Regardless of the specific techniques, the path to optimization follows these high-level steps:
* Understand and agree the context in which the proposed optimization exists
* Assess the current state of the proposed optimization
* Agree what the future state and priorities of the organization should be, focusing on simplification and value
* Ensure the optimization has the appropriate level of stakeholder engagement and commitment
* Execute the improvements in an iterative way
* Continually monitor the impact of optimization
https://www.bmc.com/blogs/itil-guiding-principles/

Reference: https://www.bmc.com/blogs/itil-incident-management/