The success of a just-in-time (JIT) implementation effort is dependent, partially, upon the availability of simulation and modelling tools that are both easy to use and adaptable for modelling real-world systems. During JIT implementation, some subsystems will continue to retain their ‘push’ characteristics. Thus, an effective simulation software language must offer the flexibility to model JIT elements, while preserving the traditional features for modelling push elements. We propose a control paradigm for implementing the ‘pull’ control structure of JIT systems. The paradigm is based upon the concept of ‘kanban satisfaction’ which is used to provide the control structure which permits the pulling of material to take place. The concepts are extended to describe the modelling requirements for interfacing JIT modules with traditional push systems.