A New Dimension in
What is Software-as-a-Service?
Evaluating Service Desk Solutions: On-Site and Software-as-a-Service (SaaS)
The purpose of this article is to provide an aid for decision makers evaluating service desk solutions, and specifically
explores how the new Software-as-a-Service (SaaS) model compares to traditional on-site implementations.
ASP is not SaaS
Here at Vivantio we are particularly concerned with evidence from analysts, industry bodies and customers
regarding the misleading way in which some vendors are jumping on the bandwagon and presenting their offerings
as SaaS when in fact they are not. This article attempts to make clear the distinction between SaaS and other models
such as outsourced hosting and ASP.
Vivantio Service Desk is available for both on-site install and as a true SaaS service.
Single tenant vs Multi tenant
The first and most important distinction to make between the two models is that traditional on-site implementations
and ASP solutions are single-tenant whereas SaaS is multi-tenant.
A multi-tenant application has one shared interface and one instance of the application, with data securely
separated for each customer. This enables the vendor to leverage economies of scale by sharing the back-end
infrastructure, reducing support costs and upgrading all customers at once.
A single-tenant application has one implementation per customer. Back-end infrastructure is not entirely shared
amongst customers. Each customer has to be upgraded separately. This is true whether the application is installed on
the customer’s premises or at a data centre such as in an Application Service Provider (ASP) model.
ASP is not SaaS because it involves single-tenant applications and at least some of the back-end infrastructure is
dedicated to individual customers.
Both the Service Desk Institute and analysts at Gartner have warned customers to be wary of vendors branding their
solutions as SaaS when they are not multi-tenant.
Gartner define SaaS as “the delivery of multi-tenant service from a remote location over an internet protocol (IP)
network via a subscription-based outsourcing contract.” They also warn that it is important to note the differences
between SaaS and hosting or application outsourcing, observing that: “Because the SaaS/on-demand market is
‘hot’, many suppliers are rebranding their hosting or application management or application outsourcing
capabilities as SaaS/on-demand.”
The Service Desk Institute also commented in a recent report: “It is very important to define what SaaS is not,
particularly as many legacy vendors with Application Service Provider (ASP) models will try to persuade buyers that
they are offering SaaS products, when they aren't.”
Comparing the models
Traditional on-site (single-tenant) Software-as-a-Service (multi-tenant)
Large upfront licence costs and annual support costs. Recurring subscription fee, pay as you go.
Additional cost required to take advantage of major All upgrades included and provided more frequently.
new versions. Released infrequently.
Bug fixes and updates applied separately to each Bug fixes and updates applied to all customers at once
customer’s system, usually via periodic patches. resulting in stable software and lower costs.
Increasing number of users increases the base cost Increasing number of users does not increase the base
(e.g. hardware platform and related support) cost (no hardware to maintain)
Licensing costs therefore not aligned directly with Licensing costs therefore directly aligned with usage.
Requires hardware deployment, server licences, Does not require server hardware. Uses existing internet
backup and networking infrastructure. connection and web browser.
Physical and system security are mainly the SaaS vendor provides security, typically at data centre
responsibility of the customer. standard which are difficult to achieve on-site.
Customisation usually requires development input from Customisation usually performed via API and/or
the vendor. application configuration. Less input from vendor.
Total Cost of Ownership and Return on Investment
Both TCO and ROI are underpinned by the vendor’s business model, which differs significantly between on-site and
SaaS vendors, creating very different vendor/customer relationships.
A traditional software vendor charges a high upfront cost for the licences and consulting services, and a smaller
annual fee for support. After the initial sale, they won’t get much from the customer. So they rely on customers
upgrading every few years, or becoming dissatisfied with their existing vendor and switching.
Compare this to SaaS vendors. Because the business model is based on ongoing revenue and continual upgrades,
they can gradually introduce changes to their application to maintain compatibility with new platforms. They never
have to “encourage” customers to upgrade every few years. And because there are no inflated upfront costs, high
levels of customer service have to be central to what they do in order to retain customers.
The traditional model benefits from customer churn and relies on high upfront costs. The SaaS model relies on
customer satisfaction and steady subscription fees.
Getting back to our original issues of TCO and ROI, we can see that in the traditional model there are high upfront
licence fees for the customer and every 3 or 4 years they will be forced to purchase an upgrade or replace the
In addition, studies have shown that the cost of the software is typically a small proportion of the total cost of running
and maintaining on-premise systems.
Gartner estimates that more than 75% of the IT budget is spent maintaining and running existing systems and
Both Gartner and IDC found that customers spend up to four times the cost of their software licence per ye to own
and manage their applications.
The chart below indicates what studies typically find when comparing traditional and SaaS implementations.
As the chart shows, the initial outlay is significantly higher for on site implementations; SaaS then catches up a little
over the first few years but whenever on site systems or the underlying platform get replaced or upgraded there is
another jump. By comparison, SaaS costs are smooth over time even when a customer switches from one SaaS
provider to another.
While there is wide variation in the actual figures, the principle seems to hold true and the TCO of on
on-site systems is
the same or higher than equivalent SaaS implementations.
These results also indicate that positive return on the investment is realised more quickly in the SaaS model because
there is very little upfront outlay.
Is SaaS Here to Stay?
It is tempting to think that SaaS is just another marketing trick but the evidence clearly indicates otherwise.
The Software and Information Industry Association (SIIA) predicts that 10 million companies will be using SaaS in the
next 3 years.
Gartner have said that the SaaS market will more than double, reaching $14.8 billion in 2012, and 25% of all business
software will be delivered under a SaaS model by 2011.
A recent Gartner survey also found that 9 out of 10 companies will be increasing their use of SaaS in 2009, citing cost
effectiveness and ease of deployment as primary reasons.
IDC expects SaaS growth to rise by more than 40% in 2009.
Vivantio’s own sales figures also make interesting reading. We offer our service desk system for both on-site install and
as a SaaS service, with software costs (not TCO) breaking even over 3 years. We let customers decide which model
suits them best and so far over 80% have chosen the SaaS model, again for reasons of cost and ease of deployment.
Software-as-a-Service is a viable and proven model which has sustainable benefits and there are some tangible
differences which enable decision makers to objectively determine which model is most appropriate in a given
In the service desk market, legacy vendors are confusing the issue by touting ASP and other models as SaaS.
Customers should be careful to establish whether a vendor is offering a true multi-tenant SaaS solution, or risk missing
out on some of the real benefits of the SaaS model.
Service Desk Institute (SDI)
The Software and Information Industry Association (SIIA)
:: 01934 424840
:: Vivantio Ltd.
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