When should we build an app instead of customizing Dynamics 365?

The question comes up in almost every implementation project, and the answer has consequences for many years.

The order that pays off

Try the standard functionality first. If it cannot do the job, configure it. If the need is still unmet, consider a custom app. Each step provides more flexibility and requires more maintenance, and most people reconsider when they see what the final step costs over time.

When an app is still the right choice from the outset

Two cases: the task is performed by people who should not have access to the CRM at all, or it needs to be done on a mobile device under conditions where a full CRM interface is impractical. In those cases, a simple app is both cheaper and better.

The cost people forget

An app must be kept up to date when Dynamics 365 is updated, when someone leaves, and when the process changes. Standard functionality is maintained by Microsoft. That is the most important difference in the long term.