That phrase "The Supplier That Kept Changing the Price" is famously associated with Eliyahu Goldratt's influential business novel, "The Goal: A Process of Ongoing Improvement" (1984). It's a central example illustrating the devastating impact of unreliable suppliers and uncontrolled variability on a manufacturing system.

1. The Scenario in "The Goal":

   • Alex Rogo's plant relies on a critical component supplied by "UniCo."
   • UniCo periodically increases the price of this component without notice or justification.
   • The plant managers have little choice but to accept the price hikes because the component is unique and crucial for their product.
   • These unpredictable price increases disrupt the plant's financial planning, cost control, and ultimately, its ability to meet production goals and make a profit.

2. Why It's a Powerful Lesson:

   • Illustrates the Impact of Variability: The constantly changing price is a form of uncontrolled variability. Goldratt emphasizes that variability (in anything – lead times, quality, or costs) is a major enemy of efficiency and flow in any system. It creates uncertainty and forces reactive, firefighting behavior.
   • Highlights Dependency Risk: The plant is critically dependent on a single supplier for a key part. This dependency makes them vulnerable to the supplier's actions, including arbitrary price changes.
   • Exposes Flawed Supply Chain Relationships: The relationship is purely transactional and exploitative. There's no partnership, collaboration, or mutual benefit. The supplier holds all the power, and the buyer suffers.
   • Connects to the Theory of Constraints (TOC): The changing price component acts as an external constraint on the plant's ability to achieve its goal (making money). The plant's internal efforts to improve are constantly undermined by this unpredictable external factor. It shows that solving internal problems isn't enough if external constraints aren't managed.

3. Key Lessons for Businesses:

   • Supplier Reliability is Crucial: Price stability and predictability are often as important as the absolute price level itself. Unpredictable costs cripple planning.
   • Manage Dependencies: Avoid single-sourcing critical components unless you have strong contracts, leverage, or a truly irreplaceable relationship. Diversification is key.
   • Build Partnerships, Not Just Transactions: Collaborate with suppliers on cost management, forecasting, and problem-solving. Shared goals lead to more stable outcomes.
   • Understand Your True Costs: Fluctuating input prices make it hard to calculate accurate product costs and set profitable selling prices.
   • Contracts Matter: Long-term agreements with clear pricing mechanisms (e.g., tied to indices, fixed periods, volume discounts) are essential for stability.
   • Buffer Against Variability: Have safety stock or alternative sources strategically placed to mitigate the impact of supplier issues (including price hikes).

4. Real-World Relevance:

   • Commodity Markets: Suppliers of raw materials (metals, chemicals, agricultural products) are notorious for price volatility due to global markets, geopolitics, and weather.
   • Complex Supply Chains: Multi-tiered supply chains amplify variability. A small change at a lower tier can ripple up as unexpected costs or delays.
   • Supplier Financial Instability: A struggling supplier might suddenly raise prices to improve cash flow, passing its problems onto customers.
   • Lack of Transparency: Suppliers may change prices due to internal inefficiencies or market shifts they don't communicate effectively.

In essence, "The Supplier That Kept Changing the Price" is a potent symbol of the chaos and inefficiency caused by uncontrolled external variability and poor supply chain management. It teaches businesses that achieving operational goals requires not only optimizing internal processes but also actively managing dependencies and building resilient, predictable supplier relationships. If you're facing this issue, focus on diversification, negotiation of stable contracts, and building stronger partnerships with your suppliers.

Is this referring to the specific example from "The Goal," or are you dealing with a real-world supplier issue? I can provide more targeted advice if you share more context!