Software as a Service (SaaS)
       •  Definition:  Software  as  a  Service  (SaaS),  a.k.a. 
        ondemand software, is a software delivery model in which 
        software and its associated data are hosted centrally and 
        accessed using a thin-client, usually a web browser over 
        the internet. – Wikipedia • Simply put, SaaS is a method 
        for  delivering  software  that  provides  remote  access  to 
        software as a webbased service. The software service can 
        be purchased with a monthly fee and pay as you go. 
           Software as a Service (SaaS)
            SaaS is a model of software deployment where an 
               application is hosted as a service provided to customers 
               across the Internet. 
            Saas alleviates the burden of software 
               maintenance/support
                 but users relinquish control over software versions and 
                  requirements.
            Terms that are used in this sphere include 
                 Platform as a Service (PaaS) and 
                 Infrastructure as a Service (IaaS)
       Applicability of SAAS 
        Enterprise Software application:
             Sharing  of  data  between  internal  and  external  users  e.g.  : 
         Salesforce CRM application
        Single user Software application
         Runs on single user computer and serves 1 user at a time e.g. : 
         Microsoft office
        Business Utility SaaS - Applications like Salesforce automation are 
         used by businesses and individuals for managing and collecting 
         data, streamlining collaborative processes and providing actionable 
         analysis.    Popular    use    cases    are   Customer  Relationship 
         Management (CRM), Human Resources and Accounting.
        Social Networking SaaS - Applications like Facebook are used by 
         individuals for networking and sharing information, photos, videos, 
         etc.
  Consideration for SAAS Application 
  development
           Important factors for good design of 
           SAAS model
            Three distinct points that separates a well-design from a 
               poorly designed SAAS application
                  scalability
                 Multi tenant efficient
                  configurable
            Scalability- maximizing concurrency, and  efficient use of 
               resources
                 i.e. optimizing locking duration, statelessness, sharing pooled 
                  resources such as threads and network connections, caching 
                  reference data, and partitioning large databases