Despite the fact that multitenancy is a distinction that has been around for a very long time, even in 2025, there is a considerable degree of confusion in the EHS software space when it comes to the importance of multitenancy. That confusion may be intentionally perpetuated by EHS software companies that are unable to support multitenancy. We will try to clarify its importance here.

Companies that are considering Software-as-a-Service (SaaS) hear all sorts of things from EHS software vendors hoping to tap into the momentum of cloud computing.  Among the most common claims is that multitenancy is a “techie” thing that doesn’t need to be part of the conversation.  Many other vendors go as far as saying “sure, we can do multi-tenant, single-tenant, whatever you need!”— they’ll say anything to win the sale.

Unfortunately, those vendors simply do not understand what they are talking about.  Multitenancy is a major shift in computing and requires an all new approach to software architecture and delivery models.  It is transformational, and customers who intend to buy the next generation of EHS software should spend the time to understand the real meaning and importance of multitenancy.

Multitenancy is the core foundation of modern SaaS in the EHS market and beyond

Multitenancy is the core foundation of modern SaaS, and it shouldn’t be taken lightly, generalized, or massaged into something that suits a vendor’s self-serving interpretation of a SaaS model.  Having experienced first-hand the true benefits of multitenant SaaS, I can’t fathom how SaaS would have delivered those benefits if it hadn’t been multitenant. It’s not a trivial attribute that vendors can make optional — it’s fundamental to the offering.  For example, imagine companies like Salesforce, Google, or Amazon offering a “single-tenant” solution side-by-side with their multitenant clouds?  One could argue that a company offering a single-tenant solution cannot be a serious contender in offering multi-tenant SaaS.

I would also add that single-tenant (hybrid) cloud applications are worse than on-premise installments.  Why?  Because they are fake clouds.  In these instances, a customer is, in fact, outsourcing maintenance of their application to a vendor that is not equipped for that maintenance.  No single vendor in the EHS software industry is large enough to undertake maintenance of the single-tenant infrastructure on behalf of their customers, regardless how inexpensive hardware may be at the time.

There are many ways to take the functions of on-premise installed software model of the 1980s and package them as services.  Some of these service delivery modes– such as ASP, single-tenant hosting, and hybrid clouds– merely relocate and reassign long-standing problems and potentially make them worse.  In a single-tenant model, user customizations may infiltrate throughout the stack in a way that makes it difficult to upgrade the performance of the stack.  The true SaaS models confront and mitigate– or even eliminate– the most vexing elements of software installation and maintenance: configurability on the fly, software maintenance, and upgrades.  It is “a tyranny of software upgrades” that kills the single-tenant model.

Let me offer a simple analogy to drive home the point as to why multitenancy matters: Tesla vs. Edison and the War of Currents.

An analogy for multitenancy vs single tenancy: AC/DC (but not the rock band) 

The War of Currents was a series of events surrounding the introduction of competing electric power transmission systems in the late 1880s and early 1890s that pitted companies against one another and involved a debate over cost and convenience of electricity generation and distribution systems, electrical safety, and a media/propaganda campaign, with the main players being the direct current (DC) based on the Thomas Edison Electric Light Company and the supporters of alternating current (AC) based on Nikola Tesla’s inventions backed by Westinghouse.

With electricity supplies in their infancy, much depended on choosing the right technology to power homes and businesses across the country.  The Edison-led group argued for DC current that required a power generating station every few city blocks (single-tenant model), whereas the AC group advocated for a centralized generation with transmission lines that could move electricity great distances with minimal loss (multitenant model).

The lower cost of AC power distribution and fewer generating stations eventually prevailed.  Multitenancy is equivalent of AC when it comes to cost, convenience, and network effect.  You can read more about how this analogy relates to SaaS in the book by Nicholas Carr, “Big Switch,” a Wall Street Journal bestseller. It’s “the best read so far about the significance of the shift to cloud computing,” said Financial Times.  While Locus has been pioneering the use of multitenancy in the EHS software space for years, most vendors have been laggards.

Given these fundamental differences between different modes of delivering software as a service, it is clear that the future lies with the multitenant model.

Whether all customer data is put onto one database or onto multiple databases is of no consequence to the customer.  For those arguing against it, it is like an assertion that companies “do not want to put all their money into the same bank account as their competitors,” when what those companies are doing is putting their money into different accounts at the same bank.

When customers of a financial institution share what does not need to be partitioned—for example, the transactional logic and the database maintenance tools, security, and physical infrastructure and insurance offered by a major financial institution—then they enjoy advantages of security, capacity, consistency, and reliability that would not be affordably deliverable in isolated parallel systems.

In enterprise cloud applications and cloud application platforms, multitenancy yields a compelling combination of efficiency and capability without sacrificing flexibility or governance.

When a software provider seeks to blur the distinctions between one technology and another, there’s usually just one reason: because they are unable to offer the superior technology to their customers, and they hope to persuade their customers that real differences are not relevant to their needs.  Multitenant platforms for enterprise on-demand applications represent genuine opportunities for customer advantage.  The reality of multitenant differentiation is acknowledged by authoritative industry analysts such as Gartner and other analyst firms

Hosting models that do not leverage multitenancy don’t belong in the same discussion as the value proposition implied by the term, “SaaS”.  Multitenancy is a difference that makes a difference.