Föreläsningar del 9 Flashcards
Flashcard 1: Q: What is the primary benefit of better sequencing in operations management?
A: Better sequencing leads to better capacity utilization by optimizing the order in which tasks are processed.
Flashcard 2: Q: What does the term “flow time” refer to?
A: Flow time refers to the total time a job (or flow unit) spends in the shop or factory, including both queue time and processing time.
Flashcard 3: Q: What is the “makespan” in operations management?
A: Makespan is the total time required to process a given set of jobs or tasks, aiming to complete them as quickly as possible.
Flashcard 4: Q: What does the “Earliest Due Date” (EDD) rule minimize?
A: EDD minimizes the maximum tardiness of jobs by prioritizing jobs with the earliest due dates.
Flashcard 5: Q: What is Johnson’s algorithm used for in sequencing?
A: Johnson’s algorithm is used for sequencing jobs in a two-resource (workstation) flow shop to minimize makespan by finding the optimal order of jobs.
Flashcard 6: Q: How do Gantt charts help in schedule monitoring and control?
A: Gantt charts help track planned schedules, showing whether jobs are on schedule, behind, or ahead, and assist in adjusting the plan accordingly.
Flashcard 7: Q: What is the primary purpose of vehicle routing and scheduling approaches?
A: Vehicle routing and scheduling approaches, like complete enumeration, aim to find the best route and minimize total delivery time, reducing operating costs and greenhouse gas emissions.
Flashcard 8: Q: What is the Poisson Process and when is it typically used?
A: The Poisson process models the random arrival of customers in a system and is usually applicable when arrival rates (λ) are relatively low, typically λ < 20.
Flashcard 9: Q: How are service times typically modeled in queuing systems?
A: Service times are often modeled using the exponential distribution, which describes the time between random events.
Flashcard 10: Q: What is the most common queue discipline in queuing systems?
A: The most common queue discipline is First Come, First Served (FCFS), where customers are served in the order they arrive.
Flashcard 11: Q: What does the code “A/B/K” represent in queuing systems?
A: “A/B/K” is a code that describes a queuing system, where A is the arrival distribution, B is the service (departure) distribution, and K is the number of servers (channels).
Flashcard 13: Q: What does “0!” equal?
A: 0! equals 1, by definition.
Flashcard 14: Q: How do you calculate 3! (three factorial)?
A: 3! = 3 × 2 × 1 = 6.
Flashcard 15: Q: How do you calculate 5! (five factorial)?
A: 5! = 5 × 4 × 3 × 2 × 1 = 120.
Flashcard 1: Q: What does the “Fewest Number of Operations Remaining” (FNO) rule prioritize?
A: FNO prioritizes jobs with the fewest operations remaining but does not consider the time required for each operation.
Flashcard 2: Q: How is flowtime calculated in operations management?
A: Flowtime is the sum of the queue time and the processing time for a job or flow unit.
Flashcard 3: Q: What is the purpose of Johnson’s algorithm in sequencing?
A: Johnson’s algorithm is used to find the optimal sequence of jobs in a two-resource (workstation) flow shop by minimizing makespan.
Flashcard 4: Q: What is the first step in applying Johnson’s algorithm?
A: List the jobs and their processing times on resources #1 and #2.
Flashcard 5: Q: How is the job sequencing determined in Johnson’s algorithm?
A: The job with the shortest processing time is sequenced first if it corresponds to resource #1, or last if it corresponds to resource #2. This process is repeated for subsequent jobs.
