Event- and time-based design of operation sequences with uncertainties in execution times

• In this paper, we introduce a complete framework for integrating the design of the manufacturing process and control system. We show how operation sequences can be designed in a modeling tool, Sequence Planner (SP), and how relations between operations may be expressed using logical conditions. An approach to convert the SP model into a constraint programming model for optimization is presented. The time-based solution is transformed to an event-based description. Due to uncertainties in execution times, some logical restrictions based on the optimal schedule are relaxed to avoid unnecessary delays. The control logics to achieve the desired operation sequences are added to the SP model. Hence, the process designer can revise the sequences if necessary, and the control designer retrieves a logical description of the optimized process that can be automatically converted to control code.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Reglerteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Control Engineering (hsv//eng)

Keyword

Constraint programming

Flexible manufacturing systems

Scheduling

Multi-product production planning

Discrete event systems

Publication and Content Type

kon (subject category)

ref (subject category)