Exploring boundaries using Independent Service Heuristics

Independent Service Heuristics (ISH) is a technique invented by the authors of Team Topologies, Matthew Skelton and Manuel Pais.

ISH is an intermediate approach that can help to introduce the principles of DDD without some of the abstract terminology that can often be a bar...

• Is the thing dependent on lots of data from multiple sources? Or fairly independent?
• Are the sources internal (under our control) or external?
• Is the input data clean or messy?
• Is the input data provided in a self-service way? Can the team consume the input data "as a...

Decide where to focus the attention.

Essentially we just need to choose an area of the business that needs to be represented in software.

This could be a user journey, a “product”, a possible business domain, a software service, an entire software application, a set of tasks for a si...

• Is the scope big enough to provide an impact? Would the scope be engaging for talented people?
• Is there sufficient value to customers and the organization that the value would be clearly recognized?

• Is this thing logically independent from other things?
• Could the team "self-serve" dependencies in a non-blocking manner from a platform?

• Are the full costs of running this thing transparent or possible to discover? Consider infrastructure costs, data storage costs, data transfer costs, licence costs, etc.
• Is the thing too interconnected with other things in the organization? Or fairly separate?
• Does the organi...

Once a candidate domain, service, application, or value stream has been identified, the next step is to go through a series of questions to identify whether we have found a good candidate for being a separate stream of change.

• Does this thing provide discrete value in a well-defined sphere of execution? 
• Can the team define their own roadmap based on what they discover is best for the product and its users or is the team always driven by the requirements and priorities of other teams?

Footprints Tours offers ‘alternative’ walking tours of cities exploring their social and cultural history.

They provide both guided and self-guided tours and have implemented a monolith website and mobile application to serve all of their customer needs.

The first step would ...

• Would it be a viable business (or "micro-business") or service?
• What would a subscription payment include?
• Is there a clearly defined customer base or segment?

• Is the thing meeting specific user needs?
• Do we know (or can we easily articulate) these user types and their needs?

• Is this thing independent enough?
• Would consumers understand or value it?
• Would it simplify execution?

• Would it be a viable business (or "micro-business") or service?
• Would it be a compelling offering?
• Could a marketing campaign be convincing?

• Would the cognitive load (breadth of topics/context switching) be bounded to help the team focus and succeed?
• Would significant infrastructure or other platform abstractions be needed?