Electrosmart.Net

Key Characteristics of SaaS

Key characteristics of software delivered by SaaS include:

Network-based access to, and management of, commercially available [not custom] software
Activities are managed from central locations rather than at each customer's site, enabling customers to access applications remotely via the Web application delivery.
Delivery models are typically closer to a one-to-many model [single instance, multi-tenant architecture] than to a one-to-one model, including architecture, pricing, partnering, and management characteristics centralized feature updating, which obviates the need for downloadable patches and upgrades.
SaaS applications are generally priced on a per-user basis – often a relatively small minimum number of users, with additional fees for extra bandwidth and storage.
SaaS revenue streams to the vendor are lower initially than traditional software license fees, but are also recurring, and therefore viewed as more predictable, much like maintenance fees for licensed software.

Maturity SaaS Architecture

Architectures for SaaS can be associated with one of four primary "maturity" levels. These levels, proposed by Microsoft, help to identify tangible architectural concepts that any web-native SaaS application can relate to.

Level 1 – ASP Like

The first level of maturity emulates the traditional application service provider [ASP] model of 1990’s software delivery.
Each customer has its own customized version of the hosted application, and runs its own instance of the application on the host's servers.

Level 2 – MultiTenant

The vendor hosts a separate instance of the application for each customer [tenant].

Rather than each instance being individually customized for the tenant, all instances use the same code implementation, and the vendor meets customers' needs by providing detailed configuration options that allow the customer to change how the application looks and behaves to its users.

Level 3 – Meta Driven Virtualization

The vendor runs a single instance that serves every customer, with configurable metadata providing a unique user experience and feature set for each one.

Authorization and security policies ensure that each customer's data is kept separate from that of other customers. The end user has no indication that the application instance is being shared among multiple tenants.

As multiple customers' data share one instance of the application, one customer's data can be logically/virtually separated from that of other customers. Multiple customers' data may be saved physically into the same data file; however, virtualization of the application ensures one customer can never see another customer's data.

Level 4 – Fully Load-Balanced Virtualized

The vendor hosts multiple customers on a load-balanced farm of identical instances, with each customer's data kept separate, and with configurable metadata providing a unique user experience and feature set for each customer.

This system is fully scalable with the number of servers and instances on the back-end increased or decreased as required to match demand. This requires no additional re-design of the application, and changes or fixes can be rolled out to thousands of tenants as easily as a single tenant.

The mission-critical auxiliary components required of all SaaS applications has lead to best of breed vendors creating tools to aid in SaaS development and operations. These vendors provide ISV commodity components that allow conversion of an existing web/web service to SaaS, or WAP-based products into a SaaS application. These tools significantly reduce the amount of time and effort required to create a SaaS application, reducing time to market, engineering cost and resource effort involved.

Next: Selling SaaS Solutions