ABC Call Center is a growing organization that handles customer inquiries and support calls for various clients. The center has a team of skilled agents with different expertise levels in handling different types of calls. The management wants to optimize the assignment of calls to agents in order to improve efficiency and customer satisfaction.The objective is to minimize the total time required to handle all calls by assigning each call type to an appropriate agent, considering the expertise of the agents.The call center receives calls of three types: Technical Support $($TS$),$ Billing Inquiries$($BI$),$ and General Queries $($GQ$).$ The agents are categorized based on their expertise in handling these call types. The table below shows the number of calls received for each type and the time required by each agent to handle each call:$$ EnteBAgent$/$ Call TypeTechnical Support$($TS$)$Billing Inquiries$($BI$)$GeneralQueries $($GQ$)$Agent $1456$Agent $2637$Agent $3824$Explain the concept of assignment models. Highlight the key characteristics and applications of assignment models.