Business processes with PHP, BPMN and DMN
The business world has created a number of technical formats in the past. Many times these have been adopted first by the Java and .Net communities. The Object Management Group has been working on new XML based standards: Business Process Model and Notation (BPMN) and Decision Model And Notation (DMN) standards. These latest standards complement the classic UML standard.
These efforts are again spearheaded by the Java community, including the Camunda BPM project. PHP is still relatively developer focused, where in the Java community business processes and other terms are much more wide spread. This includes enterprise grade content management and eCommerce tools which can benefit greatly from defining processes in the methods offered by these tools.
The PHP community has taken leaps towards the right directions with standard tools. Symfony has been a great influence in making PHP mode credible in the enterprise. The Symfony Expression Language is one of these technologies that can be adopted by PHP projects to make standards like BPMN and DMN more accessible to business users.
In a more and more fragmented world of Microservices like Decoupled CMSes you'll need to think more how you orchestrate this legions of services together. This is where a single point of controlling the flow logic will show it's strengths. Before you ever get to this stage, you should consider if Microservices are a valid option for you at all.
Some BPMN and DMN tools that are accessible to PHP developers even today: