To find the business value we can use domain classification proposed by Domain Driven Design. It classifies domains into:

• core domain

• makes the company business special
• it differs from other companies/competitors
• enables the company to earn (more) money

This is the most precious domain in the company, so we should take care of it as if it were a hen laying golden eggs. The core domain is usually built as a proprietary solution by the best developers with the highest quality. It is fully tailored to business needs, treated with the highest priority and greatest effort.

Let’s look at example:

I think it is obvious what are core domains and why are special. In this example, there is no one, but two core domains. You can have zero to many core domains, but usually one.

• generic subdomain

• does not contain anything special but is needed for the company to work
• does not differ from other companies
• can be purchased, used as SaaS, outsourced

Most often, to save time and energy to focus on the core domain, the generic subdomain is outsourced, used as SaaS, purchased, etc. In our example, we can use an external payment system and a drop shipping model where the business partner is responsible for warehouse and delivery:

or more explicit:

• supporting subdomain

This is the third and final type of domain, so if the domain is not core or generic, it is supporting 🙂 As the name suggests, it supports/helps other domains with their activities. The supporting domain:

• is necessary for the company to runs its business
• requires some level of adaptation

You may start with an existing solution and tweak or extend it to specific needs. In our example marketing and order domain use standards solutions with some customization:

How does this classification help?

It starts the discussion, on what is essential, where the value is, and how to make money. It focuses on the most important aspects of the business to be successful. It helps to prioritize efforts, including the building of customized solutions. It saves time and money to invest in the core domain, not a generic one.

Are there other classifications?

Maybe, but they are not as popular as proposed by DDD. You can always use our criteria and notation to present what is important to your business. For example the cooperation of domains by overlapping, the importance of a domain by thickness, domain size, business value:

Can domains change?

Yes, nothing stays forever, especially domains in startups, where core domain can become supportive, and generic may become the core domain, depending on where the company gets a competitive advantage and value. Domains can change and evolve during the project. New requirements or a change in requirements may affect the type and the shape of the domains – can be bigger or can be divided into smaller. The most important thing is not to stick to the original division but to redefine it on an ongoing basis.