OPMA 3306 Final Exam
Which of these two numbers is smaller: 10E3 or 0.05?
0.05
Which of these two numbers is smaller: 10E-03 or 0.05?
10E-03, or .001
Which of the two numbers is larger: 10E7 or 1,000?
10E7
How much of a normal distribution is between values located at one standard deviation above and one standard deviation below the mean?
68%
True or False. Assume a fixed cost for a process of $120,000. The variable cost to produce each unit of product is $35, and the selling price for the finished product is $50. Which of the following is the number of units that has to be produced and sold to break-even:
8,000
The expected number of customers that arrive each period:
Arrival rate
A production environment where pre-assembled components, subassemblies, and modules are put together in response to a specific customer order:
Assemble-to-order
A process structure designed to make discrete parts. Parts are moved through a set of specially designed workstations at a controlled rate:
Assembly Line
This is a basic type of process structures where equipment or processes are arranged according to the progressive steps by which the product is made:
Assembly Line
The problem of assigning all the tasks to a series of workstations so that each workstation has no more than can be done in the workstation cycle time and so that idle time across all workstations is minimized:
Assembly-line balancing
An often automated process that converts raw materials into a finished product in one contiguous process:
Continuous process
The place where inventory is positioned to allow processes or entities in the supply chain to operate independently:
Customer order decoupling point
A physical inventory taking technique in which inventory is counted on a frequent basis rather than once or twice a year:
Cycle Counting
The number of days of inventory of an item. If an item were not replenished, this would be the number of days until the firm would run out of the item (on average). Also, the inverse of inventory turn expressed in days:
Days-of-supply
Points within the supply chain where inventory is positioned to allow processes or entities in the supply chain to operate independently:
Decoupling points
The need for any one item is a direct result for some other item, usually an item of which it is a part:
Dependent demand
Here the firm works with the customer to design the product, which is then made from purchased materials, parts and components:
Engineer-to-order
After determining the significance of the model (using the ANOVA table), the next step is:
Evaluate R-square
True or False. Break-even analysis can only be used in production equipment decision making when dealing solely with fixed costs, no variable costs.
False
True or False. Fixed order quantity inventory systems are time triggered models:
False
True or False. In balancing an assembly line, workstation cycle time has to be less than the time between successive units coming off the end of the line:
False
True or False. In the majority of cases, capacity is typically fluid and easily adjusted to meet demand as demand fluctuates:
False
True or False. Little's Law states that supply chain processes can be regarded as unrelated and thus treated and analyzed separately:
False
True or False. Regarding single period inventory models, cost of reordering is an important consideration in calculating the optimal order:
False
True or False. Regarding single period inventory models, holding costs are an important consideration in calculating the optimal order:
False
You are performing a test of statistical inference. In this case, you have a p-value of 0.001. Your alpha level is 0.05. Although you have no way of knowing this, absolutely no difference of any kind exists between the groups you are testing. The null hypothesis is true. How would you describe this?
False positive
As you make the value of alpha smaller, you can avoid one kind of problem. However, another kind of problem will become more likely. Pick the right pair of problems, and in the right sequence (which gets better, which gets worse):
False positive; false negative
True or False. When ordering inventory under uncertainty, maintaining an inventory that matches the average demand will result in stockouts 2.5% of the time or less:
False. 50% of the time.
True or False. Lost profits are calculated using the Cost of Overage:
False. Cost of Underage.
True or False. The weighted moving average is the most used of all forecasting techniques:
False. Exponential smoothing is.
True or False. KPI refers to "King pin inclination," an important engineering concept:
False. Key performance indicator.
True or False. Regarding the use of Solver, to estimate weights for an optimized weighted moving average, we set the objective function to maximize RMS:
False. Minimize RMS.
True or False. Short term forecasts are those forecasts covering periods up to, and including, two years.
False. Short term is under 3 months.
True or False. Tactical forecasts are used for decisions related to strategy and aggregate demand.
False. Strategy.
True of False. In multiplicative seasonal variation, the seasonal amount is constant no matter what the trend or average amount is:
False. The seasonal amount is constant in the additive season variation.
An inventory control model where the amount requisitioned is fixed and the actual ordering is triggered by the inventory dropping to a specified level:
Fixed Order Quantity
An inventory control model that specifies inventory is ordered at the end of a predetermined time period:
Fixed-Time Period Model
The time it takes a unit to flow through a process from beginning to end:
Flow time
Which of the following is not one of the four types of forecasting described in the book? Qualitative, Time Series, Causal, Iatrogenic.
Iatrogenic
The demands for various items are unrelated to each other:
Independent demand
The stock of any item or resource used in an organization:
Inventory
These are associated with the concept of "safety stock" and are used to prevent stock outs from occurring:
Inventory Buffers
The amount on-hand plus on-order minus backordered quantities:
Inventory Position
The cost of goods sold divided by the total average value of inventory:
Inventory turn
The time needed to respond to a customer order:
Lead time
The attempt to achieve high customer service with minimum levels of inventory investment:
Lean manufacturing
A mathematical expression that relates inventory, throughput, and flow time:
Little's Law
A production environment where the product is built directly from raw materials and components in response to a specific customer order:
Make-to-order
A production environment where the customer is served on-demand from finished goods inventory.
Make-to-stock
An area where simple items that are similar in processing requirements are produced:
Manufacturing cell
What are "measures of tendency?"
Mean, median and mode
In certain data sets, notably economic income, the distribution is said to be "skewed." In this kind of distribution, the best measure of central tendency is the:
Median
Can you add, subtract, multiply and divide standard deviations?
No
Generally speaking, the "skew" in the distribution is usually thought to be because of the presence of:
Outliers
Procedures that prevent mistakes from becoming defects:
Poka-yokes
The order in which tasks must be performed in the assembly process:
Precedence relationship
Shows the relationships between different production units and how they are used depending on product volume and the degree of product standardization:
Product process matrix
The product, because of its sheer bulk or weight, remains fixed in a location. Equipment is moved to the product rather than vice versa:
Project layout
What are "measures of dispersion?"
Range, standard deviation and variance
Regarding linear regression, the differences between the values predicted by the regression equation and the actual values in the data set are called?
Residuals
A characteristic that can be used to guide the design of service systems:
Services cannot be inventoried
What are costs of maintaining inventory?
Shortage, holding, carrying and ordering costs
Which of the following is not one of the four types of forecasting described in the textbook? Qualitative, Time Series, Causal or Sigmoid.
Sigmoid. Simulation is the last one.
Inventory that involves a one-time purchase of an item, such as T-shirts for a one-time sporting event:
Single Period Model
Which of the following is not one of the common types of trend illustrated in the book: Sigmoid (S-curve), Linear, Asymptotic, Stepwise.
Stepwise
What is SAAS?
Sum, average, average, square root
What is the relationship of the variance to the standard deviation?
The standard deviation is the square root of the variance
Which of the two numbers is smaller: 10E-3 or 0.001?
They are the same.
The long-term average rate that items flow through a process:
Throughput
According to Little's Law, which of the following can be used to estimate work-in-process inventory:
Throughput times flow time
What is not a purpose of inventory?
To reduce setup (or production change) costs
The total average investment in raw material, work-in-process, and finished goods inventory. This is valued at the cost to the firm:
Total average value of inventory
True or False. A central problem in many service settings in the management of waiting time:
True
True or False. A simple moving average can be expressed as a weighted moving average (WMA) in which all the weights are equal:
True
True or False. According to lecture, data points that lie outside of the confidence bands of the model are outliers:
True
True or False. According to the algorithm provided by the text (and regarding seasonality), the final step in analyzing seasonality is to "multiply trend component by seasonal component:"
True
True or False. Bias errors occur when a consistent mistake is made:
True
True or False. Fixed order quantity inventory systems are also called EOQ or Q-model inventory systems:
True
True or False. For the purposes of assembly-line balancing, the required workstation cycle time is found by dividing production time per day by the required units of output per day.
True
True or False. Generally, reducing inventories provides an economic benefit:
True
True or False. If the sum of the task times required to produce a product is 45 minutes and the cycle time for the same product is 10 minutes, then the theoretical minimum number of workstations is 5 using the assembly line balancing procedure:
True
True or False. In assembly line balancing, the theoretical minimum number of workstations is found by a ratio of the sum of all task times divided by the cycle time:
True
True or False. In estimating a trend that has a seasonality component, the final step is to re-constitute seasonality to the predicted value you estimated:
True
True or False. In estimating a trend that has a seasonality component, the first step is to de-seasonalize the data:
True
True or False. In exponential smoothing, the term "alpha" is multiplied by an error term (deviation) calculated by the difference between the previous term's forecast and previous term's demand:
True
True or False. Regarding the use of Solver on a new problem, we said that the first step is to select "Reset All:"
True
True or False. Regarding why we forecast demand, we said that capacity is typically fixed, but demand fluctuates and may be seasonal:
True
True or False. Single period inventory problems are known as newsvendor or newsperson problems:
True
True or False. Single period inventory problems, also known as perishable inventory or newsvendor problems, are common in the fashion industry:
True
True or False. Strategic forecasts are used for decisions related to strategy and aggregated demand:
True
True or False. The "Planning Time Index" is a KPI developed regarding traffic flow and is related to daily seasonality of traffic:
True
True or False. The first step in balancing an assembly line is to specify the precedence relationships among tasks to be performed on the line:
True
True or False. The slope is significant at an alpha level of 0.05:
True
True or False. We said that, as "n" (the number of periods) of the simple moving average becomes larger, it starts to approximate the mean of the distribution:
True
True or False. When demand is not predictable, then excess capacity may be needed if servicing customers quickly is important:
True
True or False. When ordering inventory under uncertainty, maintaining an inventory that matches the average demand will result in stockouts typically 50% of the time:
True
True or False: In linear regression, R-square is the amount of systematic variance that your linear regression model accounts for:
True
Often referred to as a job shop, a process structure suited for low-volume production of a great variety of nonstandard products. Workcenters sometimes are referred to as departments and are focused on a particular type of operation:
Workcenter
This is a basic type of process structures where similar equipment or functions are grouped together:
Workcenter
The time between successive units coming off the end of an assembly line:
Workstation cycle time
