Why Custom AEM Components are required?

[sankeths53]

In any Business use-case, we can reuse 'Out of the Box ' Components like Carousel, Breadcrumb, Navigation etc., However, In many projects developers create custom components to achieve basic functionalities.

How to justify the Client that Custom components are needed?

[kautuk_sahni · Accepted solution]

There is no need of creating custom components when your work is being done by OTTB. OOTB are created using best practices that Adobe recommends for AEM. Custom components are only needed when there is a use-case that OOTB cannot fulfill.

[smacdonald2008]

AEM OOTB components covers a lot of standard functionality - like text, images, titles, etc.

However, in many sites - there is functionality like a news ticker not available with OOTB components 

What if you want a new ticker in your web site:

This is when you would need to write a custom component for use in an AEM site. AEM provides HTL to write these components. 

Hope this clears up your question.

[raj_mandalapu]

If the OOTB components are not supporting all of your requirements then you can use custom components, why people are creating custom components for basic functionalities is either he/she not aware of OOTB components or it is not easy to implement enhancements. because some times it requires additional effort to understand OOTB

But, the recommended approach is to use OOTB components first check if it does not meet all your requirements then go for custom