To help appreciate the functions these two roles play in the ongoing collaborative discussion that develops and improves services, let me describe what each in my experience has looked like when implemented effectively.
Service Engineering is perhaps the most difficult to describe, as the functions of the role span a variety of traditional roles, including Release Engineering, as well as IT Operations. Working in conjunction with the development community, this group develops the frameworks that transform bare metal and bits of byte code to reproducible on demand services that can flex within the constraints of the business. They are, in essence, the providers of the foundation of the service. They ensure that there is effective physical inventory, and that configuration information is authoritatively captured in a way that allows for reproduction as well as traversal for better understanding of dependencies. They design key elements of the datacenter, including networks, storage, and compute, and look for standardization and modularization where possible. They manage automated OS, hypervisor and application installation and configuration. They ensure effective application packaging, and consistent and repeatable builds and installations of the entire stack. They usually understand breadth and depth of the stack, and try and provide as much of an ant farm approach to providing visualization. They have a very keen eye towards service performance and tuning, and can often be found better understanding kernels and database design. They are sometimes called "Systems Engineers", "Reliability Engineers", "Release Engineers", "Operations Engineers", and "Infrastructure Engineers".
Service Management provides the management wrap around a service. They develop and tune monitoring systems, service desks, dashboards, and other items that provide a better understanding of the performance, health, and help capture and understand patterns that may be of use for the rest of the organisation, as well as the customer. They help developers and service engineers develop hooks and harnesses that they can interrogate to better understand, collect, merge, interpret and roll up key aspects of the service. They need to understand dependency trees, understand what is most meaningful to customers, engineering, and the business, and effectively represent it as this information is critical to effective service exploitation, risk management, and contractual reporting. They understand and tune IT Operations support processes and change management, and must work especially closely with Service Engineering to capture and help coordinate any automated changes.
Engagement in the Lifecycle
Both of these groups provide the key elements for which a service is provided and managed. However, they mostly produce what most would consider non-functionals, which are the items that are not very whiz-bang for the business, and are simply assumed to be there by the customer. They are usually poorly understood, rarely invested in, and ignored like plumbing until it breaks. They are typically blindly squeezed as a cost line, and are sometimes viewed as a form of janitorial function that can do magic voodoo with computers. Business people often fear putting them in front of customers, afraid that they will scare them with their quirkiness, or that they might reveal something about the infrastructure that might terrify them. Good engineers understand their importance, but often do not have enough cycles to work with them while they work on more feature development. QA often misses that effective Service Management captures much of the same sorts of data, albeit usually unfortunately only in a production sense, that they need to assure the level of product quality that is expected. These Service teams themselves often under appreciate their own role if not shown the light.
By bringing these teams to the table, there is a much more effective grasp of the entire service lifecycle. Service Engineering can help understand the demands for flex and agility and provide both the understanding, as well as grounds and execution needed to provide it. Service Management can help with understanding the services themselves, whether to better understand user experience, user exploitation, code and service quality, as well as performance and capacity, and present these back to each of the key audiences in ways that are most meaningful to them. Working together with the rest of the players within the lifecycle, they can rapidly and continuously improve. They can reduce waste, and delight customers through collaboration and preemptive service management.