Software as a service

About: Software as a service is a research topic. Over the lifetime, 8514 publications have been published within this topic receiving 136177 citations. The topic is also known as: Service as a Software Substitute & SaaSS.

Application and communication platform for connectivity based services

Abstract: Open, horizontal service platforms are described Service providers can, via network operators, load software associated with a service onto a dedicated, service platform server The service platform server is connected, via a LAN, to one or more remote devices (eg, sensors, transducers, processors, etc) The functionality associated with the service can be distributed among two or more of the entities involved in the architecture The distributed software operates and/or monitors these remote devices to implement the subscribed service

Service quality in Software-As-A-Service: Developing the SaaS-QUAL measure and examining its role in usage continuance

Abstract: Despite the need to better understand how customers of software-as-a-service (SaaS) solutions perceive the quality of these software services and how these perceptions influence SaaS adoption and use, there is no extant measure that comprehensively captures service quality evaluations in SaaS. Based on previous SERVQUAL and SaaS literature, field interviews and focus groups, a card-sorting exercise, and two surveys of SaaS using companies, we develop, refine, and test SaaS-Qual, a zones-of-tolerance (ZOT)-based service quality measurement instrument specifically for SaaS solutions. Besides validating already established service quality dimensions (i.e., rapport, responsiveness, reliability, and features), we identify two new factors (i.e., security and flexibility) that are essential for the evaluation of service quality of SaaS solutions. SaaS-Qual demonstrates strong psychometric properties and shows high nomological validity within a framework that predicts the continued use of SaaS solutions by existing customers. In addition to developing a validated instrument that provides a fine-grained measurement of SaaS service quality, we also enrich existing research models on information systems continuance. Moreover, the SaaS-Qual instrument can be used as a diagnostic tool by SaaS providers and users alike to spot strengths and weaknesses in the service delivery of SaaS solutions.

Introduction to Cloud Computing

Abstract: ion The most significant change with cloud computing is that of abstraction. As we will describe in the following section, most cloud providers provide one or more service layers to their consumers. The operational aspect of the layers supporting the service is insulated from the customer. So, a Software as a Service (SaaS) customer will interact with the application itself, but not with the operating system or hardware of the respective cloud. This key difference allows organizations that do not have the necessary system administration skills or compute facilities to leverage enterprise applications hosted by others. Many of the technologies that assist in providing these capabilities have been present for many years. Virtualization and autonomic response are areas of computing that have been well understood for decades, as has the Internet. Providers of cloud computing were able to assemble these disparate technologies into the above capabilities, ultimately defining cloud computing. Defining Cloud Computing & 3 C01 06/09/2011 11:33:45 Page 4 CLOUD COMPUTING SERVICES LAYERS Cloud computing providers provide different kinds of services to cloud computing consumers. In order to understand the different layers of service, it’s important to understand how they would relate in a noncloud computing scenario. See Exhibit 1.1. The kind of service being provided has many implications on the provider, including how they address concerns such as security, resiliency, compliance, and multitenancy. Cloud computing services fall into one of the following categories, as shown in Exhibit 1.2. Operating system Middleware Software Infrastructure as a Service Platform as a Service Software as a Service EXHIBIT 1.1 Traditional Model versus Cloud Computing Model Infrastructure as a Service Platform as a Service Software as a Service EXHIBIT 1.2 Categories of Cloud Computing Services 4 & Introduction to Cloud Computing C01 06/09/2011 11:33:45 Page 5 Infrastructure as a Service Infrastructure as a Service (IaaS) providers allow their customers access to different kinds of infrastructure. The provider typically provides this service by dividing a very large physical infrastructure resource into smaller virtual resources for access by the consumer. Sometimes the service provided is a complete virtual machine with an operating system. In other instances the service provided is simply for storage, or perhaps a bare virtual machine with no operating system. In cases where the operating system or other software is included, the cost of the required license is either amalgamated into the cost for the service, or included as an additional surcharge. IaaS providers are often service providers to other cloud providers (see Integrator). Many current Platform as a Service providers leverage IaaS providers for extra capacity on demand. One of the more popular IaaS providers is Amazon, who provides their EC2 IaaS. Platform as a Service Platform as a Service (PaaS) providers extend the software stack provided by IaaS to include middleware. Middleware generically refers to software such as a DB2 database, or runtime environments such as a Java Runtime Environment (JRE) or a Websphere application server. This middleware is a prerequisite to running more sophisticated applications, and provides a rich operating environment for the application to exploit. PaaS providers have two methods in which they facilitate the extra capacity needed for a large multitenant system. In some cases, they provide IaaS style virtual machines to the consumer. In other cases they provide an interface through which applications in the case of a runtime environment, or data in the case of a database, can be uploaded. A popular example of a PaaS is Microsoft’s Windows Azure platform. Each method has its advantages and challenges. With an IaaS style approach, the provider typically has more control and stronger separation between tenants. This approach is less efficient, however, as common overhead such as the operating system and the virtual machine itself are duplicated across multiple tenants. In the second case, the underlying infrastructure is addressed in a much more efficient manner, with a single system image and middleware overhead amortized amongst multiple clients. Conversely, the main challenge with this approach lies in the degree of separation that can be provided between tenants. A runtime environment that is not robust or a misconfigured database can allow one user to adversely affect the quality of service of other users. Cloud Computing Services Layers & 5 C01 06/09/2011 11:33:45 Page 6 Software as a Service Application as a Service, or Software as a Service (SaaS) providers as they are more commonly known, typically provide a rich web-based interface to their customers. The customer, in most cases, is completely abstracted from the nuances of the application running behind the scenes. Tenant separation is often done at the application layer, leaving a common application, platform, and infrastructure layer underneath. Popular examples of SaaS include Google Apps and Salesforce.com. SaaS providers typically increase the capacity of their systems through scale up or scale out methods—depending on the characteristics of the application. SaaS applications that scale up are usually moved to larger platforms as their capacity requirements grow. SaaS applications that scale out are typically run on large clusters of servers. As additional capacity is required, the provider adds additional machines to the cluster. As there is a significant amount of shared resources used between tenants in an SaaS environment, the ability of one tenant to affect the quality of service of other tenants is always a concern. The ability for an SaaS provider to adequately fence or insulate one tenant from another is key to maintaining quality of service. ROLES IN CLOUD COMPUTING The cloud-computing paradigm defines three key roles. These roles each have different responsibilities and expectations relative to one another. Any party might have multiple roles depending on the context. See Exhibit 1.3.

Cloud Security with Virtualized Defense and Reputation-Based Trust Mangement

Abstract: Internet clouds work as service factories built around web-scale datacenters. The elastic cloud resources and huge datasets processed are subject to security breaches, privacy abuses, and copyright violations. Provisioned cloud resources on-demand are especially vulnerable to cyber attacks. The cloud platforms built by Google, IBM, and Amazon all reveal this weaknesses. We propose a new approach to integrating virtual clusters, security-reinforced datacenters, and trusted data accesses guided by reputation systems. A hierarchy of P2P reputation systems is suggested to protect clouds and datacenters at the site level and to safeguard the data objects at the file-access level. Different security countermeasures are suggested to protect cloud service models: IaaS, PaaS, and SaaS, currently implemented by Amazon, IBM, and Google, respectively.