Custom software vs off-the-shelf: how to decide

"Should we buy or build?" comes up every time a business hits the limit of its current tools. The answer is rarely all one or all the other. Here is how to think it through without either overspending on a bespoke system or spending years fighting a platform that was never designed for you.

What off-the-shelf gives you

• Speed. You can be using it this week.
• Lower upfront cost. Subscription instead of a project.
• Proven features. Thousands of businesses have found the bugs before you.
• Updates and support included.
• Integrations with other common tools already exist.

What it costs you is fit. The software works the way its designers imagined a typical business works. Where you are typical, that is fine. Where you are not, you either change your process to match, or you work around it.

What custom gives you

• Exact fit. It does what your process needs, in the language your staff use.
• Ownership. You control the roadmap, the data and the code. See who owns the code.
• Competitive advantage. If your process is what makes you better than competitors, software that encodes it is an asset they cannot buy.
• No per-user licences. Once built, adding users is free.

What it costs you is time, money and responsibility. It has to be specified, built, tested, hosted and maintained. See our guide to custom software development costs.

The question that actually decides it

For each thing you need the software to do, ask: is this something every business like ours does, or something that makes us different?

Accounting, payroll, email, calendars, basic CRM, standard eCommerce: every business does these, and platforms do them well. Building your own is almost always a mistake.

Your quoting method, your production scheduling logic, the way you price for different customers, the workflow that lets you deliver faster than competitors: these are yours. A platform will approximate them at best. This is where custom earns its cost.

The hybrid most businesses end up with

Standard platforms for the common functions, connected to custom tools for the parts that differentiate you. An ERP such as Odoo for operations and accounts, a custom portal for customers, and integrations between them. This is why system integration matters so much: the value is in the combination.

Odoo itself sits in an interesting middle ground: off-the-shelf modules that are open source and designed to be customised. For many businesses it removes the buy-or-build dilemma entirely, because you buy the standard 80% and build the 20% inside the same system.

Warning signs you are on the wrong side

You are bending a platform too far if you have more workarounds than features, staff keep a spreadsheet alongside the system, you pay for add-ons that half do what you need, or you have been told "the platform cannot do that" more than a few times.

You are over-building if you are specifying features that exist in products you could buy, the project has no clear owner, or the justification is "we would rather own it" without a business reason.

How to decide in practice

1. List what the software must do.
2. Mark each item as common or differentiating.
3. For the common items, shortlist platforms.
4. For the differentiating items, check whether a platform can be customised to cover them (Odoo often can), or whether they need a custom build.
5. Estimate five-year cost for each option, including licences, implementation, maintenance and the cost of workarounds.
6. Talk to someone who builds both and has no reason to sell you one over the other.

That last step is what our discovery call is for. We implement platforms and build custom software, and we will tell you which you need. Read about our custom software service or request a quote.

Frequently asked questions