APM Development Cycle (APMDC) 
For a developer, the APM development cycle (APMDC) typically starts with a customer (referred to as Merchant) requirement to support authorization with a particular Service Provider. In order to accomplish integration project, the developer will need to have the following:
Service Provider Message Specifications
Specifications for supported communication protocols and requirements, such as message packaging and message exchange workflow
Requirements for providing secure message exchange
Optional at the inception phase, but also required, Service Provider Test Host Connection Details
The communication mode for the test host may be different then the desired production communication mode.
APM Certification Script
The following diagram details a typical EFT Adaptor Development Cycle:

Typical Adaptor Development Cycle