In computing, self-contained system (SCS) is a software architecture approach that focuses on a separation of the functionality into many independent systems, making the complete logical system a collaboration of many smaller software systems.[1]
Self-contained system characteristics
SCSs have certain characteristics:
- Each SCS is an autonomous web application.
 - Each SCS is owned by one team.
 - Communication with other SCSs or third-party systems is asynchronous wherever possible.
 - An SCS can have an optional service API.
 - Each SCS must include data and logic.
 - An SCS should make its features usable to end-users by its own UI.
 - To avoid tight coupling an SCS should share no business code with other SCSs.
 - Shared infrastructure should be reduced to increase availability and decrease coupling.
 
Implementations[2] create larger systems using this approach – in particular web applications. There are many case studies[3] and further links available.[4]
Self-contained systems and microservices
While self-contained systems are similar to microservices there are differences: A system will usually contain fewer SCS than microservices. Also microservices can communicate with other microservices – even synchronously. SCS prefer no communication or asynchronous communication. Microservices might also have a separate UI unlike the SCS that include a UI.[5]
Usage
There are quite a few known usages of SCS – e.g. at Otto,[6] Galeria Kaufhof,[7] and Kühne+Nagel.[8]
References
- ↑ "Self-contained Systems Website".
 - ↑ "Codecentric Blog". 12 January 2015.
 - ↑ "Case Studies on the SCS website". scs-architecture.org. Retrieved 2023-08-01.
 - ↑ "Links on the SCS website".
 - ↑ "Self-contained Systems Website: SCS vs. Microservices".
 - ↑ "Architecture principles (used to develop the Otto shop)".
 - ↑ "Kaufhof Blog".
 - ↑ "From Monolith to Microservices". kuehne-nagel.github.io. Retrieved 2023-08-01.