Software as a service

"SaaS" redirects here. Not to be confused with Security as a service.

Software as a service (SaaS /sæs/^[1]) is a software licensing and delivery model in which software is licensed on a subscription basis and is centrally hosted.^[2][3] SaaS is also known as on-demand software, web-based software, or web-hosted software.^[4]

SaaS is considered to be part of cloud computing, along with several other as a service business models. ^[5][6]

SaaS apps are typically accessed by users of a web browser (a thin client). SaaS became a common delivery model for many business applications, including office software, messaging software, payroll processing software, DBMS software, management software, CAD software, development software, gamification, virtualization,^[7] accounting, collaboration, customer relationship management (CRM), management information systems (MIS), enterprise resource planning (ERP), invoicing, field service management, human resource management (HRM), talent acquisition, learning management systems, content management (CM), geographic information systems (GIS), and service desk management.

SaaS has been incorporated into the strategies of nearly all enterprise software companies.^[8][9]

History

Centralized hosting of business applications dates back to the 1960s. Starting in that decade, IBM and other mainframe computer providers conducted a service bureau business, often referred to as time-sharing or utility computing. Such services included offering computing power and database storage to banks and other large organizations from their worldwide data centers.^[10]

The expansion of the Internet during the 1990s brought about a new class of centralized computing, called application service providers (ASP). ASPs provided businesses with the service of hosting and managing specialized business applications to reduce costs through central administration and the provider's specialization in a particular business application. Two of the largest ASPs were USI, which was headquartered in the Washington, D.C., area, and Futurelink Corporation, headquartered in Irvine, California.^[11]

Software as a service essentially extends the idea of the ASP model. The term software as a service (SaaS), however, is commonly used in more specific settings:

• While most initial ASPs focused on managing and hosting third-party independent software vendors' software, contemporary^{[as of?]} SaaS offerings are typically provided by the software developer.^[12]
• Whereas many initial ASPs offered more traditional client-server applications, which require the installation of software on users' personal computers, later implementations can be Web applications that only require a web browser to use.^[13]
• Whereas the software architecture used by most initial ASPs mandated maintaining a separate instance of the application for each business, SaaS services can utilize a multi-tenant architecture, in which the application serves multiple businesses and users, and partitions its data accordingly. ^[14]

The acronym first appeared in the goods and services description of a USPTO trademark, filed on September 23, 1985.^[15] DbaaS (Database as a service) has emerged as a sub-variety of SaaS^[16] and is a type of cloud database.^[17]

Microsoft referred to SaaS as "software plus services" for a few years.^[18]

Distribution and pricing

The cloud (or SaaS) model has no physical need for indirect distribution because it is not distributed physically and is deployed almost instantaneously, thereby negating the need for traditional partners and middlemen. Unlike traditional software, which is conventionally sold as a perpetual license with an up-front cost (and an optional ongoing support fee), SaaS providers generally price applications using a subscription fee, most commonly a monthly fee or an annual fee.^[19] Consequently, the initial setup cost for SaaS is typically lower than the equivalent enterprise software. SaaS vendors typically price their applications based on some usage parameters, such as the number of users using the application. However, because in a SaaS environment customers' data reside with the SaaS vendor, opportunities also exist to charge per transaction, event, or other units of value, such as the number of processors required.^[20]

The relatively low cost for user provisioning (i.e., setting up a new customer) in a multi-tenant environment enables some SaaS vendors to offer applications using the freemium model.^[20] In this model, a free service is made available with limited functionality or scope, and fees are charged for enhanced functionality or larger scope.^[20]

A key driver of SaaS growth is SaaS vendors' ability to provide a price that is competitive with on-premises software. This is consistent with the traditional rationale for outsourcing IT systems, which involves applying economies of scale to application operation, i.e., an outside service provider may be able to offer better, cheaper, more reliable applications.^[21]

Architecture

Most SaaS providers offer a multi-tenant architecture. With this model, a single version of the application, with a single configuration (hardware, network, operating system), is used for all customers ("tenants"). To support scalability, the application can be installed on multiple machines (called horizontal scaling). In some cases, a second version of the application is set up to offer a select group of customers access to pre-release versions of the applications (e.g., a beta version) for testing purposes. This is contrasted with traditional software, where multiple physical copies of the software — each potentially of a different version, with a potentially different configuration, and often customized — are installed across various customer sites.^[22]

Although an exception rather than the norm, some SaaS providers use mechanisms such as virtualization to manage a large number of customers in place of multitenancy.^[23] Whether multitenancy is a necessary component of software as a service is debatable.^[24]

Vertical vs horizontal SaaS

Horizontal SaaS and vertical SaaS are different models of cloud computing services.^[25] Horizontal SaaS targets a broad variety of customers, generally without regard to their industry. Some popular examples of horizontal SaaS vendors are Salesforce and HubSpot. Vertical SaaS, on the other hand, refers to a niche market targeting a narrower variety of customers to meet their specific requirements.^[26]

Characteristics

Although not all software-as-a-service applications share all the following traits, the characteristics below are common among many of them:

Accelerated feature delivery

SaaS applications are often updated more frequently than traditional software,^[27] in many cases on a weekly or monthly basis. This is enabled by several factors:

• The application is hosted centrally, so an update is decided and executed by the provider, not by customers.^{[citation needed]}
• The application only has a single configuration, making development testing faster.^{[citation needed]}
• The application vendor does not have to expend resources updating and maintaining backdated software versions because there is only one version.^{[citation needed]}
• The application vendor has access to all customer data, expediting design and regression testing.^{[citation needed]}
• The service provider has access to user behavior within the application (usually via web analytics), making it easier to identify areas worthy of improvement.^{[citation needed]}

Accelerated feature delivery is further enabled by agile software development methodologies.^[28] Such methodologies, which evolved in the mid-1990s, provide a set of software development tools and practices to support frequent software releases.^{[citation needed]}

Open integration protocols

SaaS applications predominantly offer integration protocols and application programming interfaces (APIs) that operate over a wide area network.^{[29][better source needed][30]}

The ubiquity of SaaS applications and other Internet services and the standardization of their API technology has spawned the development of mashups, which are lightweight applications that combine data, presentation, and functionality from multiple services, creating a compound service.^{[citation needed]} Mashups further differentiate SaaS applications from on-premises software as the latter cannot be easily integrated outside a company's firewall.^{[original research?]}

Collaborative (and "social") functionality

Inspired by the development of different internet networking services and the so-called web 2.0 functionality, many SaaS applications offer features that let their users collaborate and share information.^{[citation needed]}

For example, many project management applications delivered in the SaaS model offer—in addition to traditional project planning functionality—collaboration features letting users comment on tasks and plans and share documents within and outside an organization. Several other SaaS applications let users vote on and offer new feature ideas.^{[citation needed]}

Although some collaboration-related functionality is also integrated into on-premises software, (implicit or explicit) collaboration between users or different customers is only possible with centrally hosted software.^{[citation needed]}

OpenSaaS

OpenSaaS refers to software as a service (SaaS) based on open-source code. Like SaaS applications, Open SaaS is a web-based application hosted, supported, and maintained by a service provider. While the roadmap for Open SaaS applications is defined by its community of users, upgrades and product enhancements are managed by a central provider. The term was coined in 2011 by Dries Buytaert, creator of the Drupal content management framework.^[31]

Andrew Hoppin, a former Chief Information Officer for the New York State Senate, has been a vocal advocate of OpenSaaS for government, calling it "the future of government innovation." He points to WordPress and Why Unified as a successful example of an OpenSaaS software delivery model that gives customers "the best of both worlds, and more options. The fact that it is open source means that they can start building their websites by self-hosting WordPress and customizing their website to their heart's content. Concurrently, the fact that WordPress is SaaS means that they don't have to manage the website at all -- they can simply pay WordPress.com to host it."^[32]

Adoption drivers

Several important changes to the software market and technology landscape have facilitated the acceptance and growth of SaaS:

• The growing use of web-based user interfaces by applications, along with the proliferation of associated practices (e.g., web design), continuously decreased the need for traditional client-server applications. Consequently, traditional software vendor's investment in software based on fat clients has become a disadvantage (mandating ongoing support), opening the door for new software vendors' offering a user experience perceived as more "modern".
• The standardization of web page technologies (HTML, JavaScript, CSS), the increasing popularity of web development as a practice, and the introduction and ubiquity of web application frameworks like Ruby on Rails or Laravel (PHP) gradually reduced the cost of developing new software services and enabled new providers to challenge traditional vendors.
• The increasing penetration of broadband Internet access enabled remote centrally hosted applications to offer speed comparable to on-premises software.
• The standardization of the HTTPS protocol as part of the web stack provided universally available lightweight security that is sufficient for most everyday applications.
• The introduction and wide acceptance of lightweight integration protocols such as Representational State Transfer (REST) and SOAP enabled affordable integration between SaaS applications (residing in the cloud) with internal applications over wide area networks and with other SaaS applications.

Adoption challenges

Some limitations slow down the acceptance of SaaS and prohibit it from being used in some cases:

• Because data is stored on the vendor's servers rather than on-premises, data security becomes an issue, particularly with intellectual property.^[33][34][35]
• SaaS applications are hosted in the cloud, far away from the application users. This introduces latency into the environment; for example, the SaaS model is not suitable for applications that demand response times in milliseconds (OLTP).
• Multi-tenant architectures, which drive cost efficiency for service providers, limit customization of applications for large clients, inhibiting such applications from being used in scenarios (applicable mostly to large enterprises) for which such customization is necessary.^{[citation needed]}
• Some business applications require access to or integration with customers' current data. When such data are large in volume^[vague] or sensitive (e.g. end-user's personal information), integrating them with remotely hosted software can be costly or risky or can conflict with data governance regulations.
• Constitutional search/seizure warrant laws do not protect all forms of SaaS dynamically stored data. The result is that a link is added to the chain of security where access to the data, and, by extension, misuse of these data, are limited only by the assumed honesty^{[incomprehensible]} of third parties or government agencies able to access the data on their recognizance.^{[36][37][38][39]}
• Organizations that adopt SaaS may find they are forced into adopting new versions, which might result in unforeseen training costs, an increase in the probability that a user might make an error or instability from bugs in the newer software.^{[citation needed]}
• Should the vendor of the software go out of business or suddenly EOL the software, the user may lose access to their software unexpectedly, which could destabilize their organization's current and future projects, as well as leave the user with older data they can no longer access or modify.^{[citation needed]}
• Relying on an Internet connection means that data is transferred to and from a SaaS firm at Internet speeds rather than the potentially higher speeds of a firm's internal network.^[40]
• The Ability of the SaaS hosting company to guarantee the uptime level agreed in the SLA (Service Level Agreement)^{[citation needed]}
• The reliance on SaaS applications and services can lead to SaaS sprawl within enterprises. These disparate applications and services can become challenging to maintain technically and administratively, leading to the proliferation of shadow IT. ^{[41] [42]}

The standard model also has limitations:

• Compatibility with hardware, other software, and operating systems.^[43]
• Licensing and compliance problems (unauthorized copies of the software program putting the organization at risk of fines or litigation).^{[citation needed]}
• Maintenance, support, and patch revision processes.^{[citation needed]}

Healthcare applications

According to a survey by the Healthcare Information and Management Systems Society, 83% of US IT healthcare organizations are now using cloud services, with 9.3% planning to, whereas 67% of IT healthcare organizations are currently running SaaS-based applications.^[44]

Data escrow

Software as a service data escrow is the process of keeping a copy of critical software-as-a-service application data with an independent third party. Similar to source code escrow, where critical software source code is stored with an independent third party, SaaS data escrow applies the same logic to the data within a SaaS application. It allows companies to protect and ensure all the data that resides within SaaS applications, protecting against data loss.^[45]

There are many and varied reasons for considering SaaS data escrow, including concerns about vendor bankruptcy,^[46][47] unplanned service outages, and potential data loss or corruption.^{[citation needed]} Many businesses either ensure that they are complying with their data governance standards or try to enhance their reporting and business analytics against their SaaS data.^{[citation needed]}

Criticism

One notable criticism of SaaS comes from Richard Stallman of the Free Software Foundation, who refers to it as Service as a Software Substitute (SaaSS).^[48] He considers the use of SaaSS to be a violation of the principles of free software.^[49] According to Stallman:

With SaaSS, the users do not have even the executable file that does their computing: it is on someone else's server, where the users can't see or touch it. Thus it is impossible for them to ascertain what it really does, and impossible to change it.

See also

• Application security
• Application service provider
• Cloud-based integration
• Games as a service
• Hybrid SaaS
• Servicizing

References

1. Panker, Jon; Lewis, Mark; Fahey, Evan; Vasquez, Melvin Jafet (August 2007). "How do you pronounce IT?". TechTarget. from the original on 28 November 2016. Retrieved 24 May 2012.
2. Turner, Brian. "What is SaaS? Everything you need to know about Software as a Service". TechRadar. from the original on 25 June 2020. Retrieved 4 August 2020.
3. "Definition of Software as a Service (SaaS) - Gartner Information Technology Glossary". Gartner. from the original on 29 September 2020. Retrieved 4 August 2020.
4. "What is Software as a Service (SaaS): A Beginner's Guide - Salesforce". Salesforce.com. from the original on 2018-09-27. Retrieved 2018-09-27.
5. Chai, Wesley; Casey, Kathleen. "What is SaaS (Software as a Service)? Everything You Need to Know". Tech Target. from the original on 2022-03-24. Retrieved 2022-03-24.
6. Twomey, Stephen (6 September 2022). "Software as a Service: An Overview of Cloud Computing, SaaS, and Other Infrastructures". Kennected. from the original on 14 September 2022. Retrieved 14 September 2022.
7. "IT Channel Glossary". CompuBase. March 2013. from the original on 5 February 2021. Retrieved 13 February 2013.
8. . www.ibm.com. Archived from the original on 2015-03-13.
9. Fox, A.; Patterson, D. (3 Jan 2014). Engineering Software as a Service: An Agile Approach Using Cloud Computing. Strawberry Canyon LLC. ASIN B00CCEHNUM.
10. OECD (2015-10-05). OECD/G20 Base Erosion and Profit Shifting Project Addressing the Tax Challenges of the Digital Economy, Action 1 - 2015 Final Report. OECD Publishing. ISBN 978-92-64-24104-6. from the original on 2021-02-05. Retrieved 2020-10-17.
11. Gaw, Jonathan (Oct 20, 1999). "Ladouceur Named CEO of FutureLink". Los Angeles Times. from the original on August 22, 2021. Retrieved August 22, 2021.
12. Software, Services. "Software as a Service (SaaS)". from the original on 2021-05-19. Retrieved 2021-05-19.
13. "What is SaaS (Software as a Service)? Everything You Need to Know". SearchCloudComputing. from the original on 2021-05-19. Retrieved 2021-05-19.
14. "What is Multi-Tenant". www.ibm.com. from the original on 2023-06-01. Retrieved 2023-06-01.
15. "USPTO Service Mark". Alexandria, VA: USPTO. from the original on 2013-04-04. Retrieved 2019-05-19.
16. Ferrari, Elena (2010). Access Control in Data Management Systems. Synthesis Lectures on Data Management. Morgan & Claypool Publishers. p. 77. ISBN 978-1-60845-375-7. Retrieved 2012-02-13. [...] a new emerging option is represented by the Database as a Service (DbaaS) paradigm [...]. DbaaS is regulated by the same principles as Software as a Service (SaaS) and basically means the delivery of the typical functionalities of a database management system in the cloud.
17. Mullins, Craig. "What is database as a service (DBaaS)?". Data Management. from the original on 2023-06-01. Retrieved 2023-06-01.
18. "Microsoft describes software plus services". InfoWorld. 26 July 2007. Retrieved 7 February 2017.
19. Levinson, Meridith (2007-05-15). . CIO. Archived from the original on 2009-07-04. Retrieved 2015-03-24.
20. Byron Deeter and Ryan Jung (July 2013). "Software as a Service Pricing Strategies" (PDF).
21. "Build vs. Buy: How to Know When to Buy Software or Build It Yourself". Business 2 Community. 20 January 2017. from the original on 2020-02-22. Retrieved 2020-02-22.
22. Hacigümüş, Hakan; Balakrishna, R. Iyer; Chen, Li; Mehrotra, S. (2002). "Executing SQL over encrypted data in the database-service-provider model". Proceedings of the 2002 ACM SIGMOD international conference on Management of data. pp. 216–227. CiteSeerX 10.1.1.64.8974. doi:10.1145/564691.564717. ISBN 978-1581134971. S2CID 6241358.
23. Wainewright, Phil (19 October 2007). "Workstream prefers virtualization to multi-tenancy". ZDNet (World Wide Web log). CBS Interactive. from the original on 27 January 2016. Retrieved 22 January 2016.
24. Carraro, Gianpaolo (21 June 2008). "I can't believe we are still talking about whether saas == multi-tenancy..." MS Developer network (blog). Microsoft. from the original on 12 June 2020. Retrieved 24 April 2011.
25. Muppidathi, Anbu (July 10, 2020). "Horizontal to Vertical to Micro-SaaS". Forbes. from the original on August 13, 2021. Retrieved August 13, 2021.
26. Koeppel, Johannes. "Council Post: How Vertical SaaS Is Disrupting The Fintech Giants". Forbes. from the original on 2022-05-18. Retrieved 2022-05-18.
27. Creese, Guy (18 May 2010). "SaaS vs. Software: The Release Cycle for SaaS Is Usually (Not Always) Faster". Blog. Gartner. from the original on 28 October 2011. Retrieved 24 April 2011.
28. Kuhnen, Eric (8 January 2008). . DevX. QuinStreet. Archived from the original on 21 May 2011. Retrieved 24 April 2011.
29. Dulin, Oleg (15 December 2015). "3 sets of APIs your SaaS platform needs". InfoWorld. from the original on 13 August 2020. Retrieved 4 August 2020.
30. Manvi, Sunilkumar; Shyam, Gopal (8 March 2021). Cloud Computing: Concepts and Technologies. CRC Press. p. 105. ISBN 9781000337952. from the original on 28 May 2023. Retrieved 12 March 2023.
31. Buytaert, Dries (24 January 2011). "Acquia product strategy and vision". Dries Buytaert weblog. from the original on 6 October 2014. Retrieved 5 October 2014.
32. Hoppin, Andrew (9 January 2014). "OpenSaaS and the future of government innovation". OpenSource.com. from the original on 12 April 2015. Retrieved 21 September 2014.
33. Lisserman, Miroslaw (20 December 2010). . Community. Forrester Research. Archived from the original on 13 August 2011. Retrieved 24 April 2011.
34. Landsberg, Alicia (2020-09-18). "Security for SaaS applications starts with collaboration". Tech Target. from the original on 2022-02-10. Retrieved 2022-03-24.
35. Hertz, Jake (April 11, 2022). "The Pros and Cons of Moving EDA to the Cloud". All About Circuits. from the original on May 17, 2023. Retrieved May 17, 2023.
36. Arthur, Charles (2010-12-14). "Google's ChromeOS means losing control of the data, warns GNU founder Richard Stallman". The Guardian. UK. from the original on 2014-02-28. Retrieved 2012-02-16.
37. Adhikari, Richard (2010-12-15). "Why Richard Stallman Takes No Shine to Chrome". Linux Insider. from the original on 2021-01-23. Retrieved 2015-03-24.
38. Stallman, Richard (2011-09-20). "Who does that server really serve?". Boston Review. GNU Project. from the original on 2019-12-27. Retrieved 15 January 2012.
39. Hill, Benjamin Mako (1 Feb 2009). "Show Me the Code". Revealing Errors. from the original on 25 February 2021. Retrieved 15 January 2012.
40. Gallaugher, John. . Catalog. Flat World Knowledge. Archived from the original on 2013-04-26. Retrieved 2012-04-21.
41. "The consequences of SaaS sprawl: A real-world study". 2 November 2021. from the original on 19 June 2022. Retrieved 19 June 2022.
42. "Enterprise app sprawl swells, with most apps outside of IT control". from the original on 2022-06-27. Retrieved 2022-06-19.
43. "Cloud Software as a Service (SaaS) in Cloud Computing. This is not right. Services". CloudComputingSec. 2011. from the original on 2012-01-13. Retrieved 2011-12-15.
44. "2014 HIMSS Analytics Cloud Survey" (PDF). Healthcare Information and Management Systems Society. June 2014. (PDF) from the original on 11 August 2021. Retrieved 22 November 2020 – via Amazon Web Services.
45. Wilson, Deborah R; BonaPart, Alexa (7 August 2009). "Develop a Framework for SaaS Application Business Continuity Risk Mitigation". Gartner. Archived from the original on March 8, 2013. Retrieved 24 April 2011.
46. May, Richard. "Software Escrow whitepaper" (PDF). UK: Virtual DCS. (PDF) from the original on 2015-02-04. Retrieved 2015-02-04.
47. "Software Escrow: Is Escrow dead?". 2012-06-14. from the original on 2016-09-24. Retrieved 2016-09-06.
48. Stallman, Richard. "Who does that server really serve?". GNU.org. The Free Software Foundation. from the original on 2023-06-09. Retrieved 2015-03-24.
49. Stallman, Richard (18 March 2010). "Who Does That Server Really Serve?". Boston Review. from the original on 23 November 2021. Retrieved 6 July 2013.