functional decomposition
The problems with functional decomposition are many and acute. At the very least, functional decomposition couples services to the requirements because the services are a reflection of the requirements. Any change in the required functionality imposes a change on the functional services. Such changes are inevitable over time and impose a painful future change to your system by requiring a new decomposition after the fact to reflect the new requirements. In addition to costly changes to the system, functional decomposition precludes reuse and leads to overly complex systems and clients.
Functional decomposition is usually time based after service A we need to call service B and service C
So it very strong coupling, because we need to call them in order.