The first danger we discussed is the community of one – the fact that custom development has only the input and funding your company can provide without the group knowledge and contributions that a wider community of users from multiple companies allows.  The second danger involves development resources for custom solutions.  Often this represents another “community of one” – in this case, one developer who is responsible for your code.

This is a potentially dangerous scenario, because software development depends on multiple areas of expertise.  There are data architects, systems analysts, developers, test analysts, business analysts, and so on.  Each brings deep expertise to the challenge – the deep business knowledge and the understanding of how to translate that into technical requirements, the best way to store and structure the data for scalability and efficiency, the best way to handle the data flow requirements both internal to your solution as well as integration to other solutions, and separation of the test function and code configuration management, in addition to the challenges of coding the required customization. 

This is not to mention the support process for custom code.  The more customization is used, the more support required, the greater the challenges of upgrading solutions around the customization become, and the more required ongoing investment from the developer.   For many companies, dependence on a single custom developer – or even a small team – may be an unacceptable risk.  Certainly you can take precautions to minimize the risk and impact on your company by storing source code, combining a mix of internal IT resources and outsourced talent, bringing in high level expertise to review design documentation for bigger development efforts, and budgeting for the required level of support after coding is complete.  However, in a world moving to the Cloud -  a world where people are looking to move system administration and support costs outside of your company -  customization needs to be very carefully reviewed for both  potential benefit and the real cost involved.