Facilities and Supply Chain practice questions

Answer: A) Lowers the transportation cost per unit shipped

Full truckloads spread fixed trip costs over more units, which lowers freight cost per unit. The trade-off is larger shipment quantities, which mean higher cycle inventory and less frequent replenishment.

• ACorrect. Each trip has largely fixed costs (driver, truck, dispatch). A full load spreads those costs over more units, so the freight cost per unit goes down.
• BIncorrect. Larger, less frequent shipments raise the order quantity. Average cycle inventory is about Q/2, so it goes up, not down. This is the main trade-off against the freight savings.
• CIncorrect. Waiting to fill a whole truck means shipments go out less often, so the time between replenishments gets longer.
• DIncorrect. This is backwards. Full truckloads use the vehicle's capacity better and usually cost less per unit than LTL.

Answer: A) Freight from many origins is consolidated at a central hub, re-sorted, and sent outbound in fuller loads

A hub-and-spoke network sends shipments through central hubs where freight is consolidated and re-sorted. This gives better load utilization at the cost of extra handling and possibly longer routes.

• ACorrect. Routing through hubs combines small shipments into fuller loads on the trunk lanes, which improves vehicle utilization. The trade-off is extra handling and sometimes longer total routes.
• BIncorrect. This describes direct (point-to-point) shipping. It avoids handling at a hub but often leads to partial, poorly utilized loads.
• CIncorrect. This describes a milk run, which consolidates freight on the vehicle route rather than at a central sorting facility.
• DIncorrect. This describes a decentralized storage network. It does not route flows through central consolidation hubs.

Answer: B) Layout Y, with a load-distance total of 700 trip-m

Multiply each pair's trips by its distance and add the products. The layout with the lower total (Y at 700 versus X at 850) needs less material handling.

• AIncorrect. Layout X does score 20(10)+10(20)+30(15)=850, but a higher load-distance total means more material travel, so X is worse.
• BCorrect. 20(15)+10(10)+30(10)=700, which is lower than Layout X's 850, so Y needs less material handling.
• CIncorrect. 35 m is just the sum of Y's distances. The load-distance score must weight each distance by its number of trips.
• DIncorrect. The trip count is the same for both layouts. What differs is the distance each load travels, so the weighted totals differ.

Answer: A) Vehicle routing

• ACorrect. It merges routes with the largest savings.
• BIncorrect. That uses other heuristics.
• CIncorrect. That isn't its use.
• DIncorrect. That's SPC.

Answer: C) High-volume movement along a fixed path

• AIncorrect. That suits cranes or forklifts.
• BIncorrect. That suits forklifts.
• CCorrect. Forklifts suit variable paths.
• DIncorrect. They suit fixed, high-volume paths.

Answer: A) Variable-path material movement without fixed conveyors

• ACorrect. They follow programmable routes.
• BIncorrect. That suits conveyors.
• CIncorrect. They move horizontally.
• DIncorrect. They move materials.

Answer: A) 336 m²

Total area = machine area × (1 + allowance) = 240 m² × 1.4 = 336 m².

• ACorrect. Machine area = 12 × 20 = 240 m². Adding 40% for aisles gives 240 × 1.4 = 336 m².
• BIncorrect. This is only the machine area. It leaves out the 40% aisle allowance.
• CIncorrect. This uses a 20% allowance (240 × 1.2) instead of 40%.
• DIncorrect. This is just the aisle allowance (0.4 × 240), not the total area.

Answer: D) Largest sum of own time plus all successor times first

The RPW heuristic gives each task a weight equal to its own time plus the times of all its successors. It then assigns tasks in descending order of weight, as long as precedence and cycle time allow.

• AIncorrect. RPW does not rank tasks by their own time in ascending order. Ranking shortest-first tends to leave the long tasks for later stations, where they are hard to fit.
• BIncorrect. This is the largest-candidate (longest task time) rule. It looks only at a task's own time and ignores the work that follows it.
• CIncorrect. This is the most-followers rule. It counts successors but does not add up their times.
• DCorrect. In RPW, a task's positional weight is its own time plus the times of every task that follows it. Tasks are ranked by this weight in descending order and assigned in that order.

Answer: B) x = 7.5

• AIncorrect. Weight by demand.
• BCorrect. (0 × 1 + 10 × 3)/4.
• CIncorrect. Use the weighted average.
• DIncorrect. Divide by total weight, 4.

Answer: D) 3

• AIncorrect. Recheck: 4,000/1,600.
• BIncorrect. Account for efficiency and round up.
• CIncorrect. Machines come in whole numbers.
• DCorrect. 4,000/(2,000 × 0.8) = 2.5, rounded up.