Systems Thinking: 6 Mental Models to Add to Your Thinking Toolbox

Systems Thinking: 6 Mental Models to Add to Your Thinking Toolbox

We all have our ways of making sense of the world. We see a situation, digest the information, and react based on our understanding. This cognitive process is built around mental models – the frameworks that shape our thoughts, understanding, and responses. In this article, I will share six systems-thinking mental models that can give you a new perspective on problem-solving and decision-making. These models are tools for your mental toolbox, each with a specific purpose to help you unravel complex systems and processes. Let me show you the power of systematic thinking.

1. Linear Organization

Seeing the world in superficial cause-and-effect relationships is tempting, like dominoes toppling in a line. This is the crux of thinking only in terms of linear organization. It’s useful when dealing with straightforward situations. However, life is more complex and requires thinking deeper than visible and immediate cause and effect.

For instance, imagine you’re baking a cake. There’s a clear start (mixing ingredients) and an end (a delicious dessert). Linear Organization helps you follow the step-by-step process, ensuring you don’t jump from whipping eggs to baking without first adding flour.

However, reality often involves complex systems that go beyond this linearity. That’s where this mental model comes in.

Thinking systematically beyond Linear Organization involves adopting a broader, more complex way of understanding business, life, and investment dynamics. In this context, linear thinking typically refers to a simplified perspective that assumes a direct cause-and-effect relationship in systems, where a change in one component leads to a predictable change in another.

However, businesses, life, relationships, and markets rarely operate in such straightforward manners. Multiple factors are at play, and the relationships between these factors can be non-linear, recursive, interconnected, or even chaotic.

The following mental models help demonstrate how thinking beyond linear organization can assist in thinking through complex problems in business, life, and investing.

2. Stock and Flow

Stock and flow is a concept rooted in economics but can apply to many situations. Think of stock as the current state of something and flow as the rate of change. This model helps you understand the dynamics of systems over time.

Consider your savings account. Your balance is the stock; the deposits and withdrawals are the flows. If you want to increase your savings, you can either boost the inflow (deposit more) or reduce the outflow (spend less). This model lets you visualize and adjust components to achieve your goals.

The Stock and Flow mental model originates from systems thinking and is used to understand the dynamics of complex systems. In this model, “stocks” represent the elements of the system that you can measure at any point in time, while “flows” are the rates at which these stocks change. The model can be pretty helpful in business and investing.

In Business:

  1. Inventory Management: Stocks can be considered the inventory a business has at any given point, while flows represent the rate at which inventory is bought, sold, or used. By understanding the relationship between these two factors, businesses can optimize their inventory levels and turnover rates to maximize profitability.
  2. Cash Flow Management: Cash on hand (stock) and income and expenses (flows) are crucial elements of business finance. A business could have a significant amount of cash on hand but a negative cash flow, indicating more cash is leaving the business than coming in. This could be a sign of trouble soon, even though the current cash stock seems large.
  3. Human Resources: Employees can be considered as a stock, and hiring, turnover, and attrition rates as flows. Understanding these dynamics can help businesses plan recruitment, retention, and development strategies.

In Investing:

  1. Valuation: The Stock and Flow model can be used to assess a company’s or an investment’s value. The stock represents the current value, and the flow could represent the company’s earnings or growth rate. Investors can look at these factors to decide whether an investment is overvalued or undervalued.
  2. Market Dynamics: In the overall market context, the stocks could represent total market capitalization, and flows could represent the rate of money entering or leaving the market. This can help investors understand market trends and sentiment.
  3. Commodities Investing: For commodities like gold, silver, or Bitcoin, the Stock-to-Flow ratio (the amount of the commodity currently available divided by the amount produced annually) can be used to predict future prices. A higher ratio suggests a lower inflation rate of the commodity’s supply, potentially increasing its price over time.

To use the Stock and Flow model effectively, it’s crucial to identify the essential stocks and flows within the system you’re analyzing, measure them accurately, and understand how they influence each other. This can provide a more holistic understanding of the system’s dynamics and help guide your decisions.

3. Iceberg Model

The iceberg model reminds us that there’s often more beneath the surface. Like an iceberg, where 90% is underwater, many issues have underlying causes that aren’t immediately apparent.

If you’re struggling with work-life balance, the visible problem might be extended hours at work. But the iceberg model encourages digging deeper. Are there systemic issues, like an overbearing boss or an unsustainable workload? Understanding these hidden elements can guide more effective solutions.

The Iceberg Model looks for the primarily hidden causes of problems. Once you get to the unseen roots of a problem, then you can create a solution for the true causes that aren’t readily apparent before researching and digging into root causes.

4. Bottleneck

A bottleneck is a point of congestion that slows down the overall system. It’s the narrowest part of the bottle, where flow is most restricted.

Let’s say you’re running a restaurant. You have a bottleneck if the kitchen can only prepare 20 meals per hour, but the waitstaff takes 30 orders. By identifying and addressing these chokepoints, you can improve overall system efficiency.

A bottleneck mental model is a powerful tool for identifying congestion points or delays in a system that restricts its overall output. To effectively use it for problem-solving, follow these steps:

  1. Identify the System: First, define the system you’re examining. This could be a production process, a workflow in your office, a supply chain, or any other process with multiple interlinked steps or components.
  2. Map the Process: Create a flowchart or diagram representing each step or stage in the process. This helps you visualize the system and how different components interact.
  3. Identify Potential Bottlenecks: A bottleneck is the slowest step that limits the system’s overall throughput. Look for areas where work piles up or where delays often occur. These are your potential bottlenecks.
  4. Analyze the Bottleneck: Once you’ve identified the bottleneck, investigate why it’s occurring. Is there a lack of resources? Insufficient skills or training? Poor coordination with other steps? Understanding the cause of the bottleneck is crucial for figuring out how to address it.
  5. Develop and Implement Solutions: The goal is to increase the bottleneck’s capacity, bringing it more in line with the rest of the system. Solutions could involve allocating more resources, improving training, streamlining processes, or improving coordination and scheduling.
  6. Monitor and Adjust: After implementing changes, monitor the system to see if the bottleneck has been alleviated. It’s also essential to look for new bottlenecks that may have emerged due to your changes. System optimization is an ongoing process that requires continual observation and adjustment.

Remember, the overall speed of a system is determined by its slowest component. By alleviating bottlenecks, you can significantly improve the efficiency and productivity of the entire system.

5. Second-Order Thinking

Second-order thinking pushes you to consider the consequences of consequences. It’s about looking beyond immediate outcomes to understand longer-term effects.

Suppose a company cuts costs by reducing employee benefits. The first-order effect is saving money. But the second-order effect might be lower employee morale, leading to decreased productivity and employee turnover. This model encourages a more profound analysis before making decisions.

Second-order thinking goes beyond an action’s immediate benefits and consequences to consider the subsequent effects that might occur. While first-order thinking is focused on immediate results, second-order thinking explores the chain of events that can unfold from those results.

The power of second-order thinking lies in its depth and foresight. It encourages a more comprehensive evaluation of potential outcomes, which can lead to more informed and strategic decision-making. Here’s why it’s more powerful:

Uncovering Unintended Consequences: First-order thinking might solve a problem in the short term, but it can also lead to unintended negative consequences down the line. Second-order thinking can help identify these potential pitfalls before they occur.

Long-Term Strategy: By considering the potential long-term effects of a decision, second-order thinking supports sustainable success. It guides you to make choices that provide immediate benefits and contribute to your long-term goals.

Competitive Advantage: Many people stop at first-order thinking because it’s easier and quicker. But by investing the time and effort to think one step further, you can gain an edge over others who only look at immediate effects.

Risk Management: Second-order thinking can help you anticipate potential challenges and obstacles, allowing for better risk management. By considering what could go wrong, you’re better prepared to mitigate these risks.

Systemic Understanding: Second-order thinking encourages you to see the bigger picture and understand how different system elements interact. This can lead to a deeper, more nuanced understanding of complex situations.

In essence, second-order thinking is like playing chess, where you don’t just consider the immediate outcome of a move but also how it will impact the rest of the game. It’s a powerful tool for making strategic, forward-thinking decisions.

6. Feedback Loop

A feedback loop involves output being recycled as input, influencing the system’s future state. There are two types: positive feedback, which amplifies changes, and negative feedback, which stabilizes the system.

A feedback loop is a process where the output of a system is fed back into the system as input, creating a continuous cycle that influences the system’s behavior. Feedback loops can be either positive, amplifying the system’s output, or negative, stabilizing the system and preventing it from spiraling out of control.

Understanding feedback loops can help us better comprehend the consequences of our actions and identify potential risks and opportunities in various situations. For instance, in investing, a positive feedback loop might involve a stock price rising due to increased demand, which, in turn, attracts more investors, further driving up the price. However, such a loop can lead to market bubbles and eventual crashes.

In our personal lives, feedback loops can play a significant role in shaping our habits and behavior. For example, consistently receiving praise for a job well done can create a positive feedback loop, motivating us to continue performing well. On the other hand, negative feedback loops can help us maintain balance in our lives by counteracting excessive behavior or habits.

By recognizing and understanding feedback loops, we can anticipate the consequences of our actions and make more informed decisions in the actions in our daily lives.

Key Takeaways

  • The linear organization mental model allows for straightforward, step-by-step problem-solving.
  • The stock and flow model helps visualize and manage dynamic changes.
  • With the iceberg model, you can uncover the underlying causes of visible problems.
  • Identifying bottlenecks can optimize system efficiency.
  • Second-order thinking prompts consideration of long-term consequences
  • Understanding feedback loops aids in predicting and influencing future outcomes.


Various mental models shape our thinking, which helps us navigate the world’s complexities. We gain new perspectives and tools to tackle complex problems by understanding and applying these six systems thinking models. Whether it’s the simplicity of linear organization, the dynamic balance of stock and flow, the in-depth analysis of the iceberg model, the efficiency drive of tackling bottlenecks, the foresight of second-order thinking, or the predictive power of feedback loops, these mental models enable a more holistic, systematic approach to decision-making and problem-solving. So, next time you face a challenge, remember these tools in your thinking toolbox and choose the one that fits best.