Stability of the supply chain based on disruption classification

Poremećaji mogu uništiti stabilnost opskrbnog lanca što rezultira poslovnim gubitkom, pa je određivanje utjecaja raznih poremećaja na opskrbni lanac značajno. Međutim, postojeće su se analize uglavnom usredotočile na stabilnost opskrbnog lanca u normalnim uvjetima, a istraživale su učinke razine zaliha na stanje sustava i izostavljale utjecaj poremećaja. S nedostatkom analize o karakteristikama poremećaja prilikom modeliranja prebacivog sustava, poremećaji su klasificirani i određeno je vrijeme provedbe svake poremećene razine. Predložena su dvojna pravila prebacivanja s obzirom na dinamiku zaliha i zastoja u isporuci. Izrađen je model prebacivog sustava opskrbnog lanca s višestrukim zastojima. Stabilnost sustava pod različitim razinama poremećaja ispitana je pomoću simulacijske metode. Rezultati pokazuju da se opseg stabilnosti koeficijenata prilagodbe zaliha smanjuje s porastom koeficijenta vremena prijevoza i udaljenosti. Klasifikacija poremećaja ima različite učinke na opskrbni lanac. Pod poremećajem na visokoj razini, razina zaliha proizvodnje značajno se mijenja, a sustav opskrbnog lanca gubi svoju stabilnost i susreće se s poteškoćama u vraćanju na stabilno stanje. Međutim, pod općim poremećajem, sustav opskrbnog lanca postupno se vraća u stabilnost. Sadašnje istraživanje obogaćuje pomaknutu metodu modeliranja opskrbnog lanca i pomaže članovima lanca da učinkovito sprječavaju i reagiraju na poremećaje.Disruptions can destroy the stability of a supply chain resulting in losses in business, thus, determining the influence of various disruptions on a supply chain is significant. However, current studies have mainly concentrated on the stability of a supply chain under normal conditions, exploring the effects of inventory level on the system state and omitting the influences of disruptions. With the lack of analysis on the characteristics of disruption when modelling switched system, disruptions were classified and the lead time of each disruption level was determined. Dual switch rules were proposed considering the stock dynamics and lead time delays. A switched system model of the supply chain with multiple delays was then constructed. System stability under different level disruptions was investigated using simulation method. Results show that the stability scope of inventory adjustment coefficients decreases as transport lead time and distance coefficients increase. Disruption classification has different effects on the supply chain. Under high level disruption, the inventory level of manufacture significantly changes, and the supply chain system loses its stability and encounters difficulty in recovering its stable state. However, under general disruption, the supply chain system recovers to stability gradually. The present exploration enriches the switched modelling method of the supply chain and helps its chain members prevent and respond to disruptions effectively

Stability of switched nonlinear systems with delay and disturbance

International audienceWe consider a class of nonlinear time-varying switched control systems for which stabilizing feedbacks are available. We study the effect of the presence of a delay in the input of switched nonlinear systems with an external disturbance. By contrast with most of the contributions available in the literature, we do not assume that all the subsystems of the switched system we consider are stable when the delay is present. Through a Lyapunov approach, we derive sufficient conditions in terms of size of the delay ensuring the global exponential stability of the switched system. Moreover, under appropriate conditions, the input-to-state stability of the system with respect to an external disturbance is established