Each circle in the diagram above is a Server. There's a "special" Server (called the Process Center) that is for Development and all the others are Process Servers (e.g. UAT, Production). Process Applications are created on the Process Center and then (typically) pushed out sequentially to Process Servers (with Production being the last Process Server).

Each Server (Process Center or Process Server) comprises two main components, a Process Server (which does everything to do with Process i.e. most things) and a Performance Data Warehouse (which handles the performance data that's generated by the Process Server). Having a separate component for performance data helps to optimise the overall performance.

Each Process Server (on a Process Center or a Process Server) comprises three main components, a BPD Engine, a Service Engine and an Event Manager. The whole thing is relatively stateless (everything lives in the database).

The BPD Engine does all the orchestration work. It pushes cases (Instances) through the BPD models and hands off (via the Event Manager) work to the Service Engine. When these discrete chunks of work are complete, the Event Manager lets the BPD Engine know and it moves on to the next thing in the BPD.

The Event Manager acts as a relay between the BPD Engine and the Service Engine. It picks up discrete pieces of work that are ready to run from the BPD Engine (e.g. System Tasks, Timers) and hands them over (complete with data etc.) to the Service Engine.

The Service Engine is the part that actually does things. While the BPD engine provides the orchestration the Service Engine performs does all the tangible stuff e.g. sends E-mails, calls Web Services etc.

Each Performance Data Warehouse (on a Process Center or a Process Server) comprises two main components, Tracking Data and Database Views.

Tracking Data is created when the Performance Data Warehouse picks up data from the Process Server.

Database Views sit on top of the Tracking Data and provide a richer data set for clients (typically reporting platforms e.g. Cognos).

Interacting with Process Centre / Process Server

Only present on Process Centers, the Process Designer is the Integrated Development Environment (IDE) for IBM BPM. It's where things are built. You would use the Process Designer to create a Business Process Diagram (i.e. to model a process) or an Integration Service (i.e. to connect to an external system).

Only present on Process Centers, the Process Center Console is where the things that are built are managed. You would use the Process Center Console to deploy a Process Application to a Process Server (e.g. to deploy into the UAT Environment).

Present on both Process Centers and Process Servers, the Process Portal is where Users do things.

Application Server stuff e.g. defines JDBC connections, LDAP integrations etc.

Contains all the out-the-box administrations functions (e.g. Process Inpector, Manage EPVs etc.) and any user-defined Administration Services.

There's very little to see here. It will tell you if there's a problem and give you some high level information about the volume of tracking data being generated.