Explain Software as service (Saas). What are the implementation issues, benefits and drawbacks and key characteristics

- Software as service (Saas) is a way of delivering application over the internet as service.

- Instead of installing and maintaining the software, you can simply access it over the internet.

- Saas application runs on Saas provider's server, where the provider manages access to the application, including security, availability and performance.

- Thus, email client such as Gmail or Hotmail and many different software solution accessible over internet could be given as an example of Saas.

- In order to understand the role between cloud consumer and cloud provider, refer following fig.

- The above fig depicts a user level control which represent that a consumer has control over the application that made available by the Saas application.

- A provider normally has significantly more administrative control at the application level.

- The responsibility of provider are to deploy, configure, update and manage the operations of the applications in order to provide it to the consumer.

Saas Implementing Issues

- According to the Microsoft Saas architecture can be classified into one of four maturity levels whose key  attributes are ad-hoc, configuration, multi tenant efficiency and scalable.

Saas architecture maturity level 1- Ad-hoc

The first level of maturity is actually no maturity at all. Each customer may have unique, customized version of an application. The application running on hosted computer server.

Saas architecture maturity level 2- Configuration

At this level many customer use a separate instances of the same application. This allow to meet varying needs of each customer by using detailed configuration options. 

Saas architecture maturity level 3- Multi tenant efficiency

It adds multi-tenancy to the second level. This results in single program instance that has the capability to serve all vendors customers.

Saas architecture maturity level 4- Scalable

Scalability is added by using multi-tier architecture.

Key characteristics of Saas

Following are the basic key characteristics of Saas

- It is network based management system and it is access from central location commercially available software rather than each customers site. 

- There is no need to access each and every customers site, as it is available on central location software.

- The application is delivered to one to many model rather than traditional one to one model.

- Saas is often used in conjunctions with large network of communications.

Benefits :

i) Browser based

Typically Saas application is very convenient and does not required any installation for application used. It is browser based, you can access application anywhere and anytime with network access.

ii) License management

Consumer can employ a single license on multiple computers at different time instead of purchasing extra license for separate computers.

iii) Centralized data administration

In Saas model, as customers point of view data are centralized administrate on cloud, so that every customer must have to access it anywhere throughout internet access.

iv) No infrastructure involvement 

Customer need not to involve with the management of providers infrastructure.

v) Pay for what you use model

Saas application model only need to pay for what you use within application. It does not required additional pay for overall application.

Drawbacks :

i) Lack of security 

Security is the major issue in Software as service model, as data is stored on the cloud.

ii) Browser dependency

If customer visit malicious network web site the browser become contaminated, subsequently when access to the Saas application it compromise the consumer data.

iii) Network dependency

As data transfer is depend on Saas firm at network speed than the higher speeds of firms internal network connections. 

iv) Latency Issue

Saas model is not suitable for the application which required instant response time such as milliseconds, data is stored in cloud far away from the end user, so the data transaction time is more as compare to the traditional approach.