Ohno and Goldratt in violent disagreement

 In a business situation involving a manufacturing plant plagued by both significant waste across various processes and a clearly identifiable bottleneck resource, Taiichi Ohno (representing Lean principles) and Eli Goldratt (representing the Theory of Constraints) could find themselves in violent disagreement, struggling to find common ground, particularly regarding inventory management.

Ohno's Perspective: Ohno, deeply rooted in the principles of the Toyota Production System, would likely focus intensely on identifying and eliminating all forms of muda (waste) throughout the entire plant. He would advocate for:

• Drastic reduction of all inventory, viewing it as a primary source of waste that hides problems and ties up capital. He would push for Just-in-Time (JIT) principles across all stages of production.
• Implementation of standard work in every process to ensure efficiency and identify deviations as opportunities for improvement.
• Continuous improvement (kaizen) initiatives at all levels, empowering workers on the gemba (shop floor) to identify and eliminate waste.
• Reducing batch sizes to improve flow and responsiveness.
• A holistic approach to waste elimination, believing that improvement in every area contributes to overall efficiency.

Goldratt's Perspective: Goldratt, on the other hand, would immediately seek to identify the single constraint that limits the plant's throughput. His primary focus would be on:

• Maximising the throughput of the constraint, ensuring it is never idle. This might involve strategically placing a buffer before the constraint to prevent starvation, even if it means holding inventory.
• Subordinating all non-constraint resources to the needs of the constraint. This means that non-bottleneck resources should work at a pace dictated by the constraint, even if they have spare capacity, to avoid building up excess inventory that the constraint cannot process.
• Elevating the constraint if possible, by investing in more capacity or improving its efficiency.
• Using Throughput Accounting to make decisions based on their impact on Throughput, Inventory, and Operating Expense, with Throughput being the primary driver. He would argue that focusing on local efficiencies outside the constraint is often wasteful.

The Violent Disagreement:

The core of their violent disagreement would likely centre on the issue of inventory management, particularly around the identified bottleneck.

• Ohno would vehemently oppose the idea of intentionally maintaining a buffer of inventory before the bottleneck. He would see this as a direct contradiction of JIT principles and a sign of not addressing the upstream problems that cause variability and potential starvation. He might argue that the buffer is simply hiding waste and preventing the implementation of true flow. He would push for reducing the inventory leading to the bottleneck, believing that it will force the upstream processes to become more efficient and reliable.
• Goldratt would argue with equal vehemence that eliminating the buffer before the bottleneck is a recipe for disaster, as it risks starving the constraint and directly reducing the plant's overall throughput (the rate at which it makes money). He would contend that Ohno's focus on eliminating all inventory is a locally optimal view that ignores the global constraint. He might point out that the idle time of non-bottleneck resources is not necessarily waste if it's preventing a build-up of inventory that the bottleneck cannot handle. He would likely see Ohno's plant-wide inventory reduction as a failure to understand the fundamental principle of the constraint limiting the entire system's performance.

Lack of Common Ground:

In this scenario, finding common ground could be extremely difficult initially because their fundamental approaches to operational improvement differ significantly:

• Holistic vs. Focused: Ohno's Lean approach is holistic, seeking to eliminate waste everywhere. Goldratt's TOC is highly focused, concentrating efforts on the bottleneck.
• Inventory as Waste vs. Necessary Buffer: Ohno views almost all inventory as negative. Goldratt sees strategic inventory (buffers) as potentially necessary to protect throughput at the constraint.
• Local Efficiency vs. Global Throughput: Ohno's emphasis on standard work and waste reduction in every process could be seen by Goldratt as promoting local efficiencies that don't necessarily translate to increased global throughput. Goldratt's focus on the bottleneck might be seen by Ohno as neglecting significant waste in other areas.

The disagreement could become "violent" in the sense of a strong, irreconcilable clash of philosophies and proposed actions. Each might see the other's approach as fundamentally flawed and detrimental to the plant's performance. Ohno might accuse Goldratt of condoning waste, while Goldratt might accuse Ohno of ignoring the system's leverage point and risking reduced profitability.

It would likely require a significant shift in perspective from one or both individuals, perhaps through data demonstrating the impact of their respective approaches on overall throughput and the plant's financial performance, to even begin to find common ground. Without such compelling evidence and a willingness to understand the other's core principles, they could remain locked in a violent disagreement with no apparent middle ground.

My Commentary on Probable Results:

From my understanding, a company wholeheartedly adopting Lean principles is likely to experience a more gradual but potentially widespread improvement across the organisation. Initially, they might see quick wins in reducing obvious waste and improving flow in less complex areas. However, achieving significant results, especially in terms of overall lead time reduction and consistent quality, often requires a sustained effort and cultural shift throughout the entire organisation. This can take a considerable amount of time, potentially months to years, as processes are meticulously analysed and improved, and employees are trained and empowered. The end result can be a highly efficient and responsive organisation with reduced costs and improved quality across the board.

In contrast, a company focusing on the Theory of Constraints and its principles is likely to see more rapid and dramatic improvements in specific key areas, particularly concerning throughput and on-time delivery. By identifying and focusing intensely on the bottleneck, the company can quickly leverage its most critical resource to increase output. The implementation of drum-buffer-rope and buffer management can lead to noticeable results within weeks or months. However, the initial focus might be narrower, and the benefits might be less immediately apparent in non-bottleneck areas. The long-term success depends on the company's ability to continuously identify and address new constraints as the system evolves. The end result can be a significant increase in profitability and a strong competitive advantage due to improved throughput and shorter lead times on critical paths.

It's also probable that the most successful companies will eventually find a way to integrate elements of both philosophies. TOC can provide the strategic focus on the most critical limitations, while Lean offers a comprehensive toolkit for waste reduction and continuous improvement across all processes, including those both upstream and downstream of the constraint.