Firestone Plant in Decatur, Illinois

Worker Retaliation as the Cause of Firestone Tyre Defects

A nationwide product manufacturer discovers a recurring defect in a significant number of its products. By examining the production codes stamped on each item, investigators determine that a vast majority of the defective items originate from one specific factory, out of the dozen factories the company operates. Based solely on this finding, what is the most logical initial conclusion?

Pinpointing a Manufacturing Defect

Interpreting Defect Data

Responding to a Localized Production Failure

A national coffee chain receives numerous complaints about burnt-tasting espresso shots. The company tracks every shot pulled using a unique code that identifies the store location. After reviewing data from one month across three of its highest-volume stores, it finds the following:

• Store X: 20,000 shots pulled, 200 complaints (1% complaint rate)
• Store Y: 15,000 shots pulled, 1,950 complaints (13% complaint rate)
• Store Z: 22,000 shots pulled, 220 complaints (1% complaint rate)

Based on this data, what is the most effective initial step for the company to take to solve the problem?

A smartphone manufacturer discovers that 5% of its flagship model's screens are failing prematurely. By analyzing the serial numbers, the company traces the screens back to two different suppliers:

• Supplier Alpha: Provided 50% of the total screens and accounts for 92% of the reported failures.
• Supplier Beta: Provided 50% of the total screens and accounts for 8% of the reported failures.

An executive proposes halting all future screen orders from both Supplier Alpha and Supplier Beta until a full investigation is complete. From a logistical and problem-solving standpoint, what is the most significant flaw in this proposal?

A car manufacturer has received an unusual number of warranty claims for engine failures in a specific model. The company builds this engine at three different plants. Each engine has a serial number that identifies its manufacturing plant and date. Arrange the following problem-solving actions into the most logical and efficient sequence.

When a product defect is observed across a wide geographic area, it indicates that the root cause must be a fundamental design flaw affecting all production facilities equally.

A large food company is investigating reports of contamination in its packaged food products, which are made at several different factories. Match each data pattern discovered during the investigation with its most likely underlying cause.

A national car company finds a defect in the braking system of a specific model. The company has three plants (A, B, C) that assemble this model. If an analysis of warranty claims shows that 95% of the brake failures occurred in cars assembled at Plant B, the root cause is most likely a ______ issue, not a design flaw.

Evidence Linking Defective Tyres to Union Workers During Labor Strife