Software as service cloud

Gurudatt Kulkarni,Sandhya Mandhare & Dipali Bendale

Electronics & Telecommunication Marathwada Mitra Mandal’s

Polytechnic, Pune, India (gurudatt.kulkarni, mandharesb, bendaledd)@mmpolyechnic.com

Shrikant Belsare Mechanical Engineering

Marathwada Mitra Mandal’s Polytechnic, Pune, India

belsaresn@mmpolytechnic.com

Niraj Patil

Computer Engineering Marathwada Mitra Mandal’s

Polytechnic Pune, India patilns@mmpolytechnic.com

Abstract— Software as a Service (SaaS) has the potential to transform the way information-technology (IT) departments relate to and even think about their role as providers of computing services to the rest of the enterprise. The emergence of SaaS as an effective software-delivery mechanism creates an opportunity for IT departments to change their focus from deploying and supporting applications to managing the services that those applications provide. A successful service-centric IT, in turn, directly produces more value for the business by providing services that draw from both internal and external sources and align closely with business goals. Despite the promised benefits of cloud computing and software as a service (SaaS) — greater flexibility and scalability, infrastructure cost avoidance, “anywhere access” to applications and data — concerns about security and governance have made some organizations hesitant to turn over a chunk of their IT systems to a third-party service provider

Keywords- SaaS, Cloud, Platform, Private

I. INTRODUCTION Cloud computing is a model for enabling convenient, on demand network access to a shared pool of configurable computing resources (e.g. networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. The fundamental concept of cloud computing is that the computing is “in the cloud”. It refers to accessing software and storing data in the “cloud” representation of the Internet or a network and using associated services. Most cloud computing infrastructures consist of services delivered through common centers and built on servers. Clouds often appear as single points of access for consumer’s computing needs.[2] Cloud computing is a model for enabling convenient, on demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction [3]

II. SERVICE MODELS Service Models: - Three main types of service levels as delivery models are:

• Software as a Service (SaaS) -: The clients may opt for ready customized application, but do not have control over background environment such as operating system, hardware or network parameters. The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web based email). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited use specific application configuration settings.

Figure 1.0 Cloud Deployment & Delivery Models • Platform as a Service (PaaS): In these types of

services, clients have control over change in application and hosting environment such as system software. But SaaS does not provide control over operating system, hardware and network parameters. The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations. With PaaS, organizations can deploy acquired or custom applications without incurring the associated upfront provisioning and

2012 International Conference on Computer Science and Service System

978-0-7695-4719-0/12 $26.00 © 2012 IEEE

DOI 10.1109/CSSS.2012.117

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ongoing maintenance and management costs of the underlying infrastructure.[5] The user organization has application control, the caveat in many cases being that the developers must be comfortable with the PaaS provider’s choices for programming languages, interfaces, development tools, database support and the like.

• Cloud Infrastructure as a Service (IaaS).-The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems; storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls). Infrastructure as a service is similar in concept to a traditional dedicated hosting service, with two major differences: Organizations tap into a shared, highly scalable pool of resources, and they pay for only what’s used on a utility basis. In other words, organizations neither have to preorder nor pay for dedicated gear sitting in an outsourced data center.

III. SOFTWARE AS SERVICE Software as a Service abbreviated as SaaS is a popular software distribution model, with customers getting delivery of the software over the World Wide Web (WWW). SaaS is characterized by simple deployment procedure, reduced expenditure in customer acquisition, flexibility- allowing support for many customers with a single version of the software. SaaS is a new model of how software is delivered. SaaS refers to software that is accessed via a web browser and is paid on a subscription basis (monthly or yearly). Different from the traditional model where a customer buys a license to software and assumes ownership for its maintenance and installation, SaaS presents significant advantages to the customer. SaaS is faster and a cost effective way to getting implemented. There are no hardware, implementation or acquisition costs involved to run the application from the customer's side. It's the responsibility of the SaaS vendor (us) to manage and run the application with utmost security, performance and reliability. Since customers pay a subscription, they have immediate access to the new features and functionality. Unlike traditional softwares where upgrades would happen once a year or once in 6 months (with the vendor coming to your office with a CD), the SaaS vendor continuously pushes new updates, fixes to the application, which is immediately accessible by the customer. This reduces the length of time it takes a customer to recognize value from the software. Since the software application is delivered as a service, its important for the vendor to focus on customer service and experience. Since this is on a subscription

model, the vendor is judged on a month-month basis and the pressure to innovate or risk losing business is greater.

Figure 2.0 Software as Service Model

A. KEY CHARACTERISTICS OF SAAS Deploying applications in a service-oriented architecture is a more complex problem than is usually encountered in traditional models of software deployment. As a result, SaaS applications are generally priced based on the number of users that can have access to the service. There are often additional fees for the use of help desk services, extra bandwidth, and storage. SaaS revenue streams to the vendor are usually lower initially than traditional software license fees. However, the trade-off for lower license fees is a monthly recurring revenue stream, which is viewed by most corporate CFOs as a more predictable gauge of how the business is faring quarter to quarter. These monthly recurring charges are viewed much like maintenance fees for licensed software. The key characteristics of SaaS software are the following: I. Network-based management and access to

commercially available software from central locations rather than at each customer’s site, enabling customers to access applications remotely via the Internet.

II. Application delivery from a one-to-many model (single-instance, multitenant architecture), as opposed to a traditional one-to-one model.

III. Centralized enhancement and patch updating that obviates any need for downloading and installing by a user. SaaS is often used in conjunction with a larger network of communications and collaboration software, sometimes as a plug-in to PaaS architecture.

B. SAAS ARCHITECTURE According to Microsoft, SaaS architectures can be classified into one of four maturity levels whose key attributes are ease of configuration, multitenant efficiency, and scalability.

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Each level is distinguished from the previous one by the addition of one of these three attributes. The levels described by Microsoft are as follows.

I. SaaS Architectural Maturity Level 1—Ad-Hoc/Custom. The first level of maturity is actually no maturity at all. Each customer has a unique, customized version of the hosted application. The application runs its own instance on the host’s servers. Migrating a traditional non-networked or client-server application to this level of SaaS maturity typically requires the least development effort and reduces operating costs by consolidating server hardware and administration.

II. SaaS Architectural Maturity Level 2—Configurability.The second level of SaaS maturity provides greater program flexibility through configuration metadata. At this level, many customers can use separate instances of the same application. This allows a vendor to meet the varying needs of each customer by using detailed configuration options. It also allows the vendor to ease the maintenance burden by being able to update a common code base.

III. SaaS Architectural Maturity Level 3—Multitenant Efficiency. The third maturity level adds multi tenancy to the second level. This results in a single program instance that has the capability to serve all of the vendor’s customers. This approach enables more efficient use of server resources without any apparent difference to the end user, but ultimately this level is limited in its ability to scale massively.

IV. SaaS Architectural Maturity Level 4—Scalable. At the fourth SaaS maturity level, scalability is added by using a multi tiered architecture. This architecture is capable of supporting a load-balanced farm of identical application instances running on a variable number of servers, sometimes in the hundreds or even thousands. System capacity can be dynamically increased or decreased to match load demand by adding or removing servers, with no need for further alteration of application software architecture.

C. ADVANTAGES OF SAAS There are some compelling advantages for both software users and software suppliers, who adopt the SaaS model of accessing and running software. These advantages are just as compelling for business consumers of software.

• Direct and Indirect Costs of using the software The traditional method of using software involves a large initial payment for purchasing the software and your rights to use it. It is then up to you to provide sufficient computer hardware resources to run that software. You’ll also have the take responsibility for administering and managing that software, which may require specialist expertise or certainly a lot of time, effort and ultimately – expense. With SaaS, you’re buying the software as-a-service, so all the

administration, management, backup and operating resources for that software is provided by your SaaS supplier. Hooray! Furthermore – since access to the software is now rented to you – there’s little or no initial payment. In the majority of cases you can buy SaaS on a comparatively modest monthly payment.

• Reliability The traditional method of installing software to your PC or network server relies on the stability of that computer. If that computer stops working, then you can’t use that software – and (subject to your backup policy) you’re likely to lose a significant proportion of your data. The traditional method of using software therefore carries a high risk service interruption and data loss. With SaaS, your SaaS supplier selects and builds the optimal computer platform upon which to run the software. As such he will invest substantially in computing and engineering resources in order to ensure he can deliver an optimal software experience to his users every time. The SaaS supplier will build his computer platform in a Data centre which provides highly reliable and resilient hosting environment for his powerful servers. He’ll create a highly resilient architecture within which his software will operate – and this will include multiple points of redundancy and comprehensive backup strategy. The end result is that your SaaS introduces a far greater level of reliability for your use of that software.

• Future-Proofing Moving to the latest version of particular software would traditionally require further capital expenditure and the arduous task of administering the upgrade on your computer or network server. With SaaS, keeping up-to-date with the latest and greatest software versions is much simpler. Since you’re buying the software “as a service”, and the software exists only on your supplier’s computer infrastructure – its up to him to administer the upgrade within the scope of the service he’s providing you. And since he’s technically best adept to the task, for the user, transitions to new software versions should be seamless and painless – both financially and operationally. [7]

• Contractual Freedom The traditional way of using software may – or may not – come with support contract obligations. Either way, you are buying use of the software up-front or financing its procurement over a fixed inflexible period. With SaaS, you’re renting access to the software – and since the software is hosted by the SaaS supplier its comparatively easy to switch-on and switch-off users. What this means is that SaaS lends itself ideally to the “on-demand” model of

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consumption. Many SaaS suppliers will offer very flexible usage contracts – even month by month, day by day or in some cases minute by minute!

• Scalability Traditionally, adding new users of software would require procurement of new licenses, new pieces of software, and designation of technical staff to help your new user “get set up”. This can be costly and time-consuming. With SaaS, the software is all operated centrally by your SaaS supplier who has invested heavily in a sophisticated, scalable and reliable computing platform. As such, if you need to add (or remove) a user, a quick instruction to your SaaS supplier will result in almost instantaneous adjustment to your service. SaaS gives your company the ability to scale up or down on-demand, allowing you to focus on your business!

Figure 2 Weighing software as a service against traditional licensed software [8]

• Accessibility With a traditional software installation, your software resides on your computer or network server. The chances are that it won’t be with you when you’re travelling, at home or generally away from the office

CONCLUSION SaaS is a novel way to optimize businesses and increase productivity. It is a cost effective business solution. There are no additional costs involved in terms of hardware installation, management, and operational costs. The responsibility lies with the vendor to manage the software with tight privacy policies, security and improve the software performance. Software as a Service (SaaS) solutions offer businesses an attractive new method for finding software solutions. Rather than licensing applications, buying whatever equipment is needed to run them, tuning the applications, debugging the install, training users and maintaining the code, SaaS customers buy access

to applications over the Internet. All patches and version upgrades are done by the independent software vendor (ISV) who hosts and sells access to the application. Software as a Service is relative new to IT industry. However, its delivery model represents a brand new and economic outsourcing model. Since SaaS technology is still under developing stage, there are many issues need to be resolved before it can be fully utilized in the business world

ACKNOWLEDGMENT Gurudatt Kulkarni one of the authors is indebted to

Principal Prof. Prasad Khatawkar for giving permission for sending the paper to the journal. Patil Niraj is also thankful to the Secretary Principal B.G. Jadhav, Marathwada Mitra Mandal for giving permission to send the paper for publication. We would also like to thanks our colleagues such as Lecturer Shrikant Belsare and Sandhya Mandhare for supporting us.

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computingv25.ppt [2] “Cloud Computing Concepts” M.Malathi Department of

Computer Science [3] P. Mell and T. Grance, "Draft NIST working definition of

cloud computing - v15," 21. Aug 2009. [4] http://www.microsoft.com/serviceproviders/saas/saasplatform

.mspx, retrieved 14 Jan 2009 [5] CDWG.com/cloudguide | 800.808.4239 Cloud Computing

Making the Cloud Achievable [6] Erin Traudt and Amy Konary, “2005 Software as a Service

Taxonomy and Research Guide,” IDC, 33453-S-0001, retrieved 11 Jan 2009

[7] http://www.comparethecloud.net/downloads/white-papers/ [8] http://www.wikinvest.com/concept/Software_as_a_Service

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