SaaS or custom software: which to choose

The Dilemma Every Technology Manager Faces

The decision between purchasing off-the-shelf software and developing custom software is one of the most important and costly choices an organization makes in its lifecycle. This decision is not just about the initial budget; it determines the path of digital growth, the speed of response to market changes, and even the organization's technical independence for years to come. In this article, instead of repeating common clichés, we help you make a decision that aligns with your business realities by examining three main criteria — Total Cost of Ownership (TCO), time-to-deployment, and vendor lock-in risk.

Total Cost of Ownership; Beyond the Purchase Price

The biggest mistake in this comparison is focusing only on the initial price. Off-the-shelf software typically has a lower purchase cost, but its total cost of ownership over 3 to 5 years can surpass that of custom software. For an accurate calculation, you need to consider four components:

• Deployment and customization cost: Off-the-shelf software is rarely installed without modifications. Configuring modules, changing forms, and integrating with existing systems (ERP, CRM, payment gateway) usually adds 20% to 40% to the initial price.
• Annual maintenance cost: Support contracts for off-the-shelf software typically cost 15% to 25% of the purchase price per year. For custom software, this figure varies between 10% and 20% of the development cost, depending on complexity.
• Infrastructure cost: Many off-the-shelf software solutions require powerful servers and database licenses. If your software is web-based and has many users, you must also calculate bandwidth and processing costs.
• Opportunity cost: If the off-the-shelf software doesn't exactly cover your workflow, you'll be forced to adapt your process to the software. This adaptation reduces productivity and is not accounted for in traditional calculations.

A Realistic Example of TCO Calculation

Suppose a trading company with 50 users needs a sales management system. A reputable off-the-shelf software is purchased for 300 million Toman. Customization and deployment costs are about 100 million Toman, and the annual support contract is 60 million Toman. Over 5 years, the total cost reaches 300 + 100 + (60×5) = 700 million Toman. In contrast, developing custom software with the same features costs about 450 million Toman, with an annual maintenance cost of 70 million Toman. The 5-year cost would be: 450 + (70×5) = 800 million Toman. The difference is only 100 million Toman, but with the custom option, you own the source code and can extend it without paying license fees.

Time-to-Deployment; Time Is an Asset Beyond Money

If your business requires rapid deployment — for example, launching an online store during the shopping season or registering customers within a specific timeframe — off-the-shelf software is the clear winner. Installing and configuring a ready-made system typically takes 2 to 8 weeks, while custom development requires at least 3 to 6 months for an initial version (MVP).

But this speed has a trap: speed at the start may lead to slowness later. Off-the-shelf software has limitations in addressing your specific needs. Every small change in your process requires a request to the vendor and waiting for the next release. These delays in today's competitive world can be more costly than waiting for custom development.

The Hybrid Approach; A Middle-Ground Solution

Many smart organizations use a hybrid approach: starting with off-the-shelf software for general needs (accounting, human resources, email) and custom development for core processes that create competitive advantage. For example, a logistics company can use off-the-shelf accounting software but develop a custom shipment tracking system. This approach maintains deployment speed while providing flexibility where it matters most.

Vendor Lock-in Risk; Getting Trapped with a Single Vendor

Vendor lock-in risk is perhaps the most overlooked and dangerous aspect of choosing off-the-shelf software. When you purchase software, you effectively become dependent on the vendor's product strategy, pricing, and development speed. This dependency has several dimensions:

• Data dependency: Your data is stored in the vendor's proprietary structure. Migrating to another system may take months, and some data may be lost during the transfer process.
• Pricing dependency: The vendor can increase license or support prices. You have no choice but to accept, since switching would cost even more.
• Technical dependency: If the vendor decides to discontinue support for the current version, you'll be forced to upgrade to a new version that may be incompatible with your hardware or systems.

A Concrete Example of Vendor Lock-in Risk

Consider a company using a popular CRM software. After two years, the vendor announces that the new version will only be offered as cloud-based and the on-premise version will no longer be supported. Your company cannot move data to the cloud for security or regulatory reasons. Now you have three options: accept the security risk, pay exorbitant fees for dedicated support, or start a costly migration project. With custom software, you have full control over the code and data, and no one can make these decisions on your behalf.

When Is Custom Software the Right Choice?

Custom software is clearly superior in the following situations:

1. You have unique processes: If your way of working differs fundamentally from competitors and this difference is your competitive advantage, off-the-shelf software will eliminate it.
2. Scalability is critical: If you anticipate rapid growth in the number of users or transaction volume, custom software can be designed precisely for that scale.
3. You need deep integration: If your software must communicate with specific hardware, sensors, or legacy systems, custom development is almost the only option.
4. Security and privacy are a priority: In sensitive industries such as healthcare, finance, or government, full control over data and code is a legal requirement.

When Is Off-the-Shelf Software Better?

In contrast, off-the-shelf software is the more logical choice if:

• Your processes are standard and similar to those of other organizations in your industry.
• You have a limited initial budget and cannot make long-term investments.
• You need rapid deployment and cannot wait 6 months.
• You don't have an internal technical team for software maintenance and development.

A Common Mistake: Ignoring Migration Costs

One of the most common mistakes in this decision-making process is ignoring the cost of migrating from the current system. If you are replacing a legacy system, you must include the costs of data transfer, user training, and running both systems in parallel. These costs typically account for 10% to 30% of the total project budget and exist in both options, but with custom software, you can carry out the migration process in stages with more control.

Another point: never assume off-the-shelf software is "bug-free." All software has bugs. The difference is that with custom software, you know the development team and can prioritize bug fixes. With off-the-shelf software, you're waiting in line behind other customers.

Summary and Decision-Making Framework

The decision between custom and off-the-shelf software is not a binary one. To make the right choice, follow this four-step framework:

1. Document your processes: Create a list of all your business processes and identify which ones are standard and which are unique.
2. Calculate the total cost of ownership for both options: Use the TCO formula and consider a 5-year time horizon.
3. Assess vendor lock-in risk: If your data is highly sensitive or you need full control, give more weight to the vendor lock-in risk.
4. Consult with your technical team: If you have an internal technical team, ask them to evaluate the maintainability of each option. If you don't, add the cost of hiring or outsourcing to your calculations.

Ultimately, remember that no option is "always right." Custom software is a smart choice for organizations seeking long-term competitive advantage and having the capacity to invest. Off-the-shelf software is more suitable for organizations that need speed and lower initial costs. If you need scalable cloud infrastructure to run your software, exploring web hosting services and cloud servers can be part of the solution. But the main decision — custom or off-the-shelf — should be based on your actual business data, not on marketing hype or fear of change.