Local Applications
Local applications are installed directly on a user’s device, a model that dominated the 1990s and remains widely used. Their biggest advantage is reliability: apps are always accessible, customizable, and available wherever the device goes.
However, maintaining these distributed installations can be challenging. Updates must be rolled out across multiple endpoints, often leading to inconsistency. Performance may also fluctuate if these apps depend on remote databases or storage resources. Security adds another layer of complexity, as corporate data must move to the device, increasing the risk of exposure and demanding strong endpoint protection.
Virtual Desktop Infrastructure (VDI)
VDI centralizes desktops and applications in a controlled environment—whether hosted on-premises or in private or public clouds. Users interact with the system through transmitted screen updates and input signals, while the data itself stays securely in one place.
This centralization simplifies updates, strengthens security, and ensures more predictable performance by keeping applications near their data sources. On the other hand, VDI requires uninterrupted connectivity and often demands specialized expertise to manage. As a result, many organizations supplement VDI with other delivery models instead of depending on it alone.
Software-as-a-Service (SaaS)
SaaS delivers software through a browser, eliminating the need for local installation or maintenance. Providers apply updates automatically, keeping applications “evergreen” for subscribers. This reduces operational overhead for IT teams and allows vendors to release features quickly.
But the subscription-based model also means customers don’t own the software—access ends when payments stop. Transitioning to a different provider can be difficult, especially when exporting data in a usable form. SaaS can also introduce familiar endpoint challenges, as user devices still interact directly with data.
The model’s rapid growth is evident. According to the Parallels Cloud Survey 2025, 80% of respondents say at least a quarter of their applications run as SaaS, with many reporting significantly higher adoption.
Desktop-as-a-Service (DaaS)
DaaS extends the SaaS model by delivering entire desktops through a managed service. Organizations access virtual desktops much like VDI but without overseeing the underlying infrastructure.
This reduces complexity while providing consolidated management, stable performance, and strong security. DaaS is especially useful when organizations need to scale quickly to support new teams or projects. However, like SaaS, DaaS is subscription-based, and the service stops if payments lapse. The model works best with standardized desktop environments—heavy customization can add complexity.
Another key consideration is data location. If desktops move to DaaS while critical applications or data remain elsewhere, users may face performance issues. Aligning desktops with the data they rely on is essential.
A Multi-Model Reality
Most organizations no longer rely on a single delivery method. They use local apps where necessary, VDI for tighter control, SaaS for streamlined access, and DaaS for scalability.
The Parallels survey highlights this blend: 85% of organizations use SaaS, but only 2% rely on it exclusively. Many combine SaaS with VDI or DaaS. Additionally, 86% of IT leaders say they are considering or planning to shift some workloads away from the public cloud, reflecting the complexity of modern delivery decisions.
What IT Leaders Need to Consider
When determining how these models fit together, organizations must assess:
Security & Compliance: Highly regulated sectors may prefer VDI for data control, while SaaS and DaaS providers offer certifications that may not apply universally.
Operational Expertise: VDI demands specialized skills; companies lacking them may adopt DaaS. SaaS’s isolated data structures may require additional tools or expertise.
Scalability & Agility: SaaS and DaaS typically allow faster expansion, though cloud-based VDI is narrowing this gap.
Geographical Factors: User locations, latency requirements, and regional data regulations influence which model performs best.
Cost Structure: VDI often requires upfront investments, while SaaS and DaaS distribute costs over time. Both direct and hidden operational costs must be evaluated.
Each application delivery model offers distinct benefits: local apps provide control, VDI enhances security, SaaS simplifies operations, and DaaS supports flexibility. Most organizations will continue using a combination of these approaches.
The optimal strategy aligns each model with the workloads it supports best, prioritizes security and compliance, and maintains adaptability for future needs. With clear objectives and thoughtful planning, IT leaders can deliver secure, high-performing access today while staying ready for whatever comes next.