Software-as-a-Service (SaaS) is gaining mindshare in the industry. In this article, published last week, Frederick Chong (from the Architecture Strategy Team at Microsoft) and his colleagues describe in details the capabilities of Service Delivery Platform.
They argue that Independent Software Vendors (ISVs) often evolved from deployments handled by their professional services organization based on specific requirements of their customers to:
...hosting solutions that are home-brewed by the software vendors themselves ... [where] the service delivery components, such as billing, metering, and logging, are built by the application vendor and integrated into the application stack.
They compare this situation to the time when developers had to seemingly write operating system level code to handle "multi-tasking" or "virtual memory management".
When SDPs become as commercially available as operating systems and database engines, software vendors will be able to concentrate on the core application development tasks, thus reducing the time and cost to market.
The article details the capabilities of an SDP from access control, single-sign-on and identity management, to order management, metering, billing, to on-boarding application tenants and support infrastructure (call center and systems).
They claim that an SDP should expose an SDK to assist ISVs in designing applications that can utilize the SDP capabilities to their fullest extend. They recommend, in particular, that the SDK implement a Dependency Injection pattern:
...to further address the separation of concern between application development and operational tasks
They summarize the motivations and principles for the SaaS hosting industry are the following:
- Considering the intense competition in the hosting industry, hosters can differentiate and streamline themselves by consolidating and leveraging the multitude of components in their existing hosting environment into a shared software service delivery platform.
- Software service providers can subscribe to a more cost effective service delivery infrastructure by adopting a shared SDP, especially when they are able to comply with the service delivery guidance given by their SDP hoster(s) and operate within the parameters of the shared infrastructure.
- The software vendor’s SaaS hosting decision is not always binary and can be hybrid, realized through a continuum of choices in between relying completely on a shared SDP to wholly self-hosting.
Both Fred and other people such as Gabriel Morgan suggest to learn from the telecommunication industry which has developed a management framework based on Fault, Configuration, Accounting, Performance and Security Management (FCAPS).