Practical Process Automation

Chapter 2. Workflow Engines and Process Solutions

After the general introduction to process automation, this chapter:

• Introduces workflow engines and process solutions

• Presents a hands-on, executable example to make things concrete

• Explores the developer experience when using process automation platforms

The Workflow Engine

As you saw in the introduction, a workflow engine is the key component for automating the control flow of a long-running process.

If you’re wondering why you should use a workflow engine instead of hardcoding processes or using batch processing or data streams, you might want to take a peek at “Limitations of Other Implementation Options”.

Core Capabilities

The core technical capabilities of a workflow engine are:

Durable state (persistence)

The engine keeps track of all running process instances, including their current state and historical audit data. While this sounds easy, durable state is still a challenge to handle, especially at scale. It also immediately triggers subsequent requirements around understanding the current state, which means you will need operations tooling. A workflow engine needs to manage transactions, too, for example, handling concurrent access to the same process instance.

Scheduling

A workflow engine needs to keep track of timing and possibly escalate if a process gets stuck for too long. Therefore, there must be a scheduling mechanism that allows the engine to become active whenever something needs to be done. This ...