In: Operations Management
1. Describe in your own words the differences between cyclic and seasonal patterns of data.
2. Zipco Printing operates a shop that has five printing machines. The machines differ in their capacities to perform various printing operations due to differences in the machines' designs and operator skill levels. At the start of the workday there are five printing jobs to schedule. The manager must decide what the job-machine assignments should be.
(a): How could a quantitative approach to decision making be used to solve this problem?
(b): What would be the uncontrollable inputs for which data must be collected?
(c): Define the decision variables, objective function, and constraints to appear in the mathematical model.
(d): Is the model deterministic or stochastic? Why?
(e): Suggest some simplifying assumptions for this problem.
Answer 1:- Seasonality can be seen as a trait of a time series where a regular and predictable variation is seen in the data which can reoccur after each year. Thus, seasonal data can be defined as the time series data which experiences the predictable change or variation which is reoccurring or repetitive over a period of one year.
On the other hand, a cyclic data can be understood as a pattern which prevails in the data exhibiting rises and falls which are not of a fixed tenure. The time period of these variations can be at least 2 years. Cyclical variations are mainly the non-seasonal element which changes in an identifiable cycle.
Answer 2:- A:- A systematic method for determining the job-matching parings can be determined with the help of a quantitative approach to decision making. This will help in minimizing the total job processing time.
B:- The uncontrollable inputs for which data must be collected are the total time taken by each job on every machine to be processed and the job machine combination which is not acceptable.
C:- Decision variables: One of every job machine combination taking the value as 1 if the combination is implemented and 0 if it is not implemented.
Objective function: The objective of this problem will be to minimize the total processing time of a job
Constraints: Each machine will be having only one job while each job will be allocated to only one machine.
D:- This model can be seen as a Stochastic as there is a variation in the job processing tie resulting from the varied set-up time for each machine along with the varied performance of the operator and so on.
E:- The assumption can be:- Let us consider that the processing ties are known and fixed.