Introduction to Queueing Theory :
Queueing theory is a branch of Operations Research because the results that we obtained can be used to make business decisions. It is the mathematical study of waiting lines. Queueing theory enables mathematical analysis of several related processes, including arriving at the queue, waiting in the queue and being served at the front of the queue. Using this theory we measure the average waiting time in the queue or the system, the expected number waiting or receiving service and the probability of encountering the system. Queueing system is a model which contains the following structure as the customers arrive and join a queue to wait for the service provided by n servers. After receiving the service, the customer exits the system.
Queueing Theory Equations :
Kendall introduced an A/B/S/K/N/Disc queueing notation that can be used in queueing theory. In A/B/S/K/N/Disc ,A is the inter arrival time distribution, B is the service time distribution, S is the number of servers, K is the system capacity, N is the calling population and Disc is the service discipline assumed.Many times the last three members are omitted, then the notation becomes A/B/S and it is assumed as K = [oo] , N = [oo] and Disc = FIFO.The Queueing Strategies are as follows :
* FIFO(First in First Out) - customers are serviced according to their order of arrival in the queue.
* LIFO(Last in First Out) - the last customer to arrive on the queue is the one who is serviced first.
* PS(Processor Sharing) - customers are serviced equally.
* SIRO (service in random order)- customers are serviced in a random order.
* PR (priority) – customers are serviced based on the p...
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...iscussion with doctor.On average: 20 minutes per activity (exponential) and arrival per hour (Poisson) calculate the average number of patients in the waiting room
2.Customers arriving at the post office in 1 queue and more servers arrival intensity 3 per minute (Poisson) service time 60 seconds (exponential) calculate: (I).number of servers which are needed to reach steady state. (ii).probability that there are no customers in the system with the calculated number of servers. (iii) average queue length with the calculated number of servers.
3. In an airport, planes land on a runway . In one runway there are 30 arrivals per hour (Poisson) 90 seconds deterministic landing time .The cost of the fuel $6000,- per hour calculate: – average length of queue. – average time that the plane land in runway. – what is the fuel costs per hour if there is a delay in queue?
30 sec) Normal Atmosphere (no. of ventilation movements/30 sec) 1
Because of the lack of organization with the health care providers in Canada, the wait times are too long and can cause serious complications to any condition the patient went in for in the first place. This situation of how the health care system can resolve wait times was brought to the government but they continue to ignore the proposals brought to them. It is possible to resolve the problems of wait times without extreme change and expenses in the health care system. The solution is to be found in the reorganization of the health care providers. Lack of assistance in the emergency room can make ones illness to become worse, therefore, causes the patient to be forced to wait in emergency rooms for an extended period of time and when they are finally seen by a health care provider, the outcome is very poor due to lack of registered staff, physicians and proper assessment(Goldman & Macpherson, 2005, p.40). The objective of this paper is to discuss and critically analyze the conditions of emergency waiting rooms. The specific issue this paper intends to explore is extensive and prolonged waiting times for patients accessing health care, patients who need urgent treatment and the vulnerability of elderly patients and children. With an in-depth critique of the barriers to health care and shortcomings of emergency rooms, strategies will be provided to enhance a health care system that makes it more accessible and efficient.
After examination, patient wait for another 5-15 minutes so see one of two admitting personnel.
13. Record observations and organize all trails and times into a table and find the average time of each trail.
b) Bottleneck is the resource that has the smallest capacity. It creates the weakest link in the overall process chain and determine the process capacity. In the other word, the process capacity is equal with the minimum capacity of its resource. Since the flow unit needs to be processed by each resource (for example there are a total “n” resources in the process), thus, the process capacity can be written as
However, patients should register again and keep waiting for the specialist out-patient clinics. In light of the evidence, a streamlined process is being implemented so as to minimize the patient time. Based on the given reference, it is probable that services diminish the time externally. In fact, patients seem to be just waiting for help. Predictability :
…the increased variability in the order process (i) requires each facility to increase the safety stock in order to maintain a given service level, (ii) leads to increased costs due to overstocking throughout the system, and (iii) can lead to an inefficient use of resources, such as labor and transportation…
(2014). Relieving emergency department crowding: Simulating the effects of improving patient flow over time. Journal of Hospital Administration, 4(1). doi:10.5430/jha.v4n1p43
Setup early warning system to inform customer about a potential stock out and supplier about a delayed order from CMO. This will help in reducing stock out situations.
As a solution for these issues, ensuring the shipments meet the daily cut-off schedule. Customers are to be informed proactively if there are any flight delays so that customers can give further instructions or they can make other arrangements. For customs issues, customers are to be educated of the different countries customs requirements and to notify customs delay.
customer at a time. They are more concerned with the quality of the service tha
Chase, R. and Apte, U. (2007). A history of research in service operations: What's the big idea?.Journal of Operations Management, 25(2), pp.375--386.
With increase population of patients visiting the emergency room, wait times are getting longer and longer. Not just wait time to see the doctors, but to be triaged by a nurse to see if a true emergency exists. The time a patient walks into the waiting room to the time when a nurse can triage the patient was taking too long. It was not safe for the patients. Furthermore, too much burden fell on the shoulder of one triage nurse. A lean process was created. An aim was to decrease the wait time for a patient to be seen by the triage nurse. The lean team measured times from the moment a patient arrived at the ER to the time when a patient was seen by a nurse. With this data at hand, they came up with a process to not only decrease the time when a patient can be assessed by the triage nurse but to alleviate the pressure on the triage nurse. The solution was to get help to
The cafeteria serves about one hundred and fifty residents of Cambridge Hall and approximately one hundred residents from Nottingham Hall. The cafeteria serves hot foods, salads, snacks, sandwiches, and beverages. The data has given me information on the percentage of customers that preferred a hot meal (interactive and precooked) to snacks, the ratio of customers that prefer precooked hot meals over an interactive hot meal, line formation, service times at the different stations, arrival times and the location of the different stations. I also learned that the peak hours of operations are from 5:00 p.m. to 6:30 p.m. and that the cafeteria has two cash registers available but only one is being utilized during the peak hours. If customers decide on a hot meal there is a 2 to 1 ratio that customers will purchase a precooked meal over an interactive meal. Through an informal customer survey, reasonable waiting times were established for the precooked line (5 minutes), the interactive line (10 minutes), and the cashier payment line (1minute).
Service management is refers to the chain management system which established the relationship between the organization and consumer. It is integrated into supply chain management system when the actual sales and customer intersect. The aim of service management system is to provide the best services to the customer through their performance. The high performance of service management can ensure the optimum services to their customer in a complex manner than the typical supply chain. Most of the time, the organization requires larger inventories and strong integration with different system and innovation. They have to be prepared with advanced information and high performance to accommodate inconsistent and uncertain demand. Moreover, Service Management must be coordinated across numerous services with large number of parts and different level of the supply chain.