The short answer
There is no default answer: anyone who always recommends one option is describing their business model, not yours.
| Option | When it fits |
|---|---|
| Buy | Common process (accounting, payroll, CRM, help desk); configuration, not code |
| Integrate | Your systems work, but information is re-keyed or reconciled between them |
| Build | Distinctive process, your own rules, and products would need rebuild-level changes |
Decide per capability: often buy ERP and CRM, integrate them, build one small app.
What each option really involves
| Buy | Integrate | Build | |
|---|---|---|---|
| You get | A widely used product with its own roadmap | Existing systems sharing data automatically | Software shaped around your process |
| First value | Usually fastest, if the fit is good | Depends on API access and data quality | Usually slowest |
| Ongoing costs | Subscriptions or hosting, administration, upgrades (often in US dollars, so exposed to exchange rates) | Monitoring, fixing breaks when vendor APIs change | Hosting, maintenance, security updates, developers |
| You control | Configuration, not the roadmap | Data flow between systems | Everything, maintenance included |
| Main risk | Bending your process, or customisation that complicates upgrades | Fragile connections, unclear source of truth | Scope growth, key-person dependency, underfunded maintenance |
A fourth path: extend a platform. Open-source business systems such as ERPNext can be configured and extended with custom fields, workflows and applications: a close fit without starting from nothing, though every customisation must be maintained through upgrades.
Questions that usually decide it
Differentiator or utility?
If customers would never notice the difference, it is a utility: buy it.
How often do rules change?
Products handle common changes (tax rates, users); frequent, specific changes favour building or extending.
Usable APIs?
Integration needs them (NetSuite REST, for example). Limits may vary by plan; price any required edition.
Who maintains it in three years?
Custom software needs funded developers, security updates and hosting for life.
Can you get your data out?
Confirm a usable export for every option, in case you change direction.
A fair decision worksheet
Weight each criterion 1 to 5, score each option 1 to 5, multiply and add. Fill it in with the people who will use and support the result, with a reason for each score.
Capability being decided: ______________________
| Criterion | Weight (1 to 5) | Buy score | Integrate score | Build score | Evidence or reason |
|---|---|---|---|---|---|
| Fit with the process as it should work | |||||
| Time until people can use it | |||||
| Five-year cost of ownership (estimates in naira, or US dollars where priced in dollars) | |||||
| Effort to maintain and upgrade | |||||
| Control over changes and priorities | |||||
| Data ownership and ability to exit | |||||
| Security and data protection obligations met | |||||
| Skills available internally or through a provider | |||||
| Dependency on a single vendor or person | |||||
| Weighted total |
- Each score has a written reason, not just a number.
- Five-year costs: licences or hosting, implementation, integration, training, support, replacement.
- Someone who will maintain the result took part in scoring.
- "Buy" scored against a specific product, after a demo of your scenarios.
- The "build" column includes ongoing maintenance, not only the first release.
The total structures the discussion; it is not the decision. If two options are close, prefer the one easier to reverse.
Signals that you are drifting into the wrong option
| You are | But | So |
|---|---|---|
| Buying | Customisations keep growing; every upgrade needs rework | You may be building inside someone else's product |
| Integrating | One record edited in three systems; nobody knows which is right | Settle the source of truth first (integration readiness checklist) |
| Building | Most requirements are standard in products you have not evaluated | Look at what exists before writing code |
Limitations
This assumes you can describe the process; if not, map it before choosing technology. It does not replace a product evaluation (for ERP, the ERP evaluation checklist), and on any path the provider matters: how to choose a technology implementation provider.
Next step
Building or extending: custom software development. Connecting what you have: business system integration. We can also help your team complete the worksheet before choosing.
Sources and further reading
Product capabilities and guidance change. These are the primary sources this article relies on, checked on the review date above.
- What is ERPNext?, ERPNext documentation (Frappe)
- API usage guidelines and limits, HubSpot Developers
- Overview of SuiteTalk REST Web Services, Oracle NetSuite Help Center
This article is general information, not legal, accounting or security advice for your specific situation. Examples are hypothetical unless stated otherwise.