4. In the class we discussed different types of queuing models used by companies/service systems to manage the waiting lines of customers and waiting time that customers spend in queues to get services at service systems. Based on your understanding, a. Define queueing system and briefly explain the major factors/characteristics that needs to be considered for designing a queueing system. (3 marks) b. Name one company/organization/firm/service system that uses a queueing system based on single/multiple channel(s), exponential/constant service time & finite-source of population. (1 mark) c. Briefly explain how the company/organization/firm/service system you mentioned in (b) uses different criteria such as population size, number of servers/channels and arrival and service patterns to manage the waiting line and waiting time for its customers. (4 marks)