Software as a Service


What is SaaS
SaaS is defined as Software as a Service.
This is treated as one of the cloud service model.
SaaS is considered as a business model as well as application delivery model.
SaaS is treated as the hosted application, so user need not to invest in hardware cost as well the cost involved in handling installation, set-up and the daily maintenance of servers and software.

What is the benefits of SaaS?
The key benefit is cost saving due to the deployment and maintenance. This model will help to save the cost of people, service and hardware required to operate the application. This will increase the profitability.
The SaaS model is emphasizing on the customization, capabilities and integration to the software application.
The SaaS model evolves, matures and gains widespread acceptance in a manner where it becomes integrated into the fabric of existing corporate data structure. Consequently it becomes a critical component spurring business transformation and streamlining existing processes to be more efficient and cost effective.
In some cases, new business processes are created that would otherwise have been unfeasible.

What is the SaaS delivery model
SaaS systems can be configured and delivered using various delivery models. It can be deployed in the cloud which means it can be hosted in off-premises (not in the user environment), on-premises (on the end user environment) or can be hybrid model (Part of the deployment in the end user environment and some part outside the user environment.)
Some of the SaaS ISVs (Independent Software Vendors) have their own data centre. These vendors are taking responsibility of the Operation, resilience, storage, security, availability, and performance of the server. As this is the key area to focus, currently some of the organizations such as Microsoft Azure and Amazon EC2 are providing the infrastructure to take care of the Operation, resilience, storage, security, availability, and performance of the server. This will bring new SaaS applications to market without a heavy investment in hardware infrastructure and a minimum involvement in operational processes.
Some of the organizations are succeeding the hybrid SaaS model. Due to substantial security or government regulation or some of the unavoidable circumstances, these organizations preserve the data centre on their own premises to store the database. And hosts the SaaS application from the cloud.
Some organizations have specific high value applications with security or compliance requirements that do not permit off-premises storage of corporate data. For such organizations, the on-premises model is the most ideal. With this model, the application is either run on the customer's servers or on servers furnished by the SaaS vendor. In this case, the application is generally treated as a conventional application that accomplishes a specific objective, thus it is deployed as a Single-Instance, Single Tenant (SIST) application.

What is the SaaS architecture model?
The current SaaS architecture is the extension of the distributed application architecture. Mostly the application layer of the thin client application will be used by the end user for the input and output of the data. The application layer will be interacting with the database tier through the business logic layer. The database tier that will store the physical data.
SaaS is treated as the both application delivery model and business model. The distribution architecture model will enhance and operate the business functionality through the application. The major responsibility with software vendor will be the focus on the application functionality.
SaaS architecture is not constraint to a single environment. The environment can be multiple for various reasons. It can be a different environment for the application layer and different environment for the database tier. Administration and monitoring, which are critical to the efficient operation of a SaaS business, are presented as components that operate across tiers.
The distribution tier is accountable for managing load balancing. The load balancing signifies a set of techniques for distributing tasks across multiple systems in order to optimize resource utilization, throughput or response time. This is an acute aspect for SaaS businesses since it confirms that customers are provided with the best level of service possible under severe resource loads.