Analysis and design of an adaptive minimum reasonable inventory control system

Effect of information update frequency on the stability of production–inventory control systems

“…John et al (1994) demonstrated the stabilizing effect of including a supply line (work-in-progress, WIP) component into an inventory and order based production control system (Towill, 1982), using block diagrams and Laplace transform. Towill et al (1997) examined the critical design parameters within an adaptive model consisting of three feedback loops-inventory error loop, desired order in pipeline loop and the lead time loop, and highlighted how the total orders in the pipeline can be used for assessing the load of the internal manufacturing pipeline. Grubbstro¨m (1998) used Laplace transform, z-transform and Net Present Value on MRP systems and showed a three-fold use of transfer functions: (1) describes production, demand and inventory dynamics in a compact way, (2) captures stochastic properties by serving as moment generating functions, and (3) assesses the cash flows up capturing the net present value in the transfer functions.…”

Assessment of fidelity of control-theoretic models of WIP regulation in networks of autonomous work systems

“…Non-linear operation rules have been developed to adjust WIP in complex networks [7]. Controltheoretic models have been used to analyze stability of production networks [8], and recommended for regulating lead times and improving customer service [9]. Control-theoretic approaches have been proposed for WIP regulation to improve operating performance, and dynamic models have been developed for WIP regulation in networks of autonomous work systems [10][11][12].…”

The value of coordination in a two-echelon supply chain

“…Indeed, the first modern control system, the Maxwell Governor, which proved so useful in the industrial revolution for controlling the velocity of steam-powered machinery, has a proportional controller in its velocity feedback loop. It is the most simple control engineering technique for this purpose, but others, such as the proportional-integral controller, also exist (see, for example Towill et al (1997)). …”