Create PHP workflow engine

We are looking for a modular and flexible PHP workflow engine to complete two primary use cases - approval and tasks

Due to limitations with PPH field length the description for each are attached as TXT files

***No PHP frameworks please***

Also there is no existing code to look at, no server access and so on - this should slot into an existing system seamlessly as it will be a replacement for a current process. In each case there will be multiple workflows as it will be different for different types of products and different sites so things like the actual field name for approved and table names etc should be able to configured easily. For example, if I choose that the product type is widgets then the backend knows widgets use table called widget_table and field called approved - if choose product type woggles then backend knows it is woggles table and field called authorised and so on.

Finally, there needs to be an easy to use front end UI which allows the creation and modification of steps along with re ordering / sorting - any time sorting is initiated it should change ordering but also flag any dependency errors etc. If look at attachment this is an idea of layout - add steps, for each step choose delay and then choose action. If action is certain type then show more fields such as detail behind sending an email etc

Happy for all "design" to be standard Bootstrap - this is not a design job per se but the interface needs to be easy to use.

Stupid prices of a few hundred pounds will be ignored - quality of work, communication and efficiency are key for us.