Bad Financial Modeling habits to avoid!

financial modelling read watch Jan 08, 2024

Traversing the Minefield: Essential Tips to Avoid Common Financial Modeling Mistakes

- Insights from Peter Ojo's Webinar


In a recent insightful webinar, financial expert and corporate trainer Peter Ojo delved into the intricate world of financial modeling. Emphasizing its pivotal role in business decision-making, Peter unraveled common pitfalls and best practices in financial modeling, highlighting the integration of AI tools like ChatGPT. This blog post encapsulates the crucial points from the webinar, offering valuable guidance for finance professionals and enthusiasts.


Unveiling the 7 Cardinal Sins of Financial Modeling

Financial models, if not carefully constructed, can lead to misleading conclusions. Here are seven detrimental habits Peter identified, which can impede the efficacy of financial models:

  1. Lack of Plan and Poor Design: Many modelers start building their financial models without adequate planning or designing. This approach can lead to a model that is not well-thought-out, making it difficult to adapt or scale as requirements change. Proper planning ensures that the model aligns with its intended purpose and is structured efficiently​​.
  2. Inconsistent Model Structure: A common mistake is not maintaining a consistent structure throughout the model. For example, starting the cash flow statement in one column and the balance sheet in another can cause confusion and errors. Consistency in structure not only makes the model easier to understand but also simplifies the process of auditing and linking different parts of the model​​.
  3. Failing to Document Assumptions and Logic: It's vital to document the assumptions and logic behind the model. Undocumented assumptions can lead to misunderstandings or misuse of the model. Proper documentation ensures that users, including the creator, can understand the basis of the model’s calculations and conclusions​​.
  4. Overlooking Scenario and Sensitivity Analysis: Neglecting scenario and sensitivity analysis in financial models can lead to an incomplete understanding of potential risks and outcomes. These analyses are crucial for evaluating the robustness of the model and understanding how different variables impact the financial outcomes​​.
  5. Overcomplicating the Model: Overcomplication refers to the use of unnecessarily complex formulas or structures within the model. This can make the model difficult to understand, audit, and adapt. A more straightforward approach with simpler formulas is often more effective and user-friendly​​.
  6. Hard Coding: Hard coding means embedding constants directly into formulas. This practice reduces the flexibility and adaptability of the model. Instead, inputs should be separated from calculations to allow for easy updates and adjustments without the need to rewrite formulas​​.
  7. Neglecting Error Checks and Validation: It's essential to build error checks and validation mechanisms to ensure the accuracy of the model. These checks help in identifying and correcting errors promptly, thus maintaining the reliability and credibility of the model​​.

Avoiding these habits is crucial for creating robust, reliable, and user-friendly financial models.


Strategies to Counter Bad Modeling Habits

Peter recommends these practices to cultivate robust, error-free financial models:

To avoid the bad habits of financial modeling, the webinar suggests the following approaches:

  1. Proper Planning and Design: Before starting to build a model in Excel, it's crucial to plan it out thoroughly. This involves asking and answering key questions that influence the model's design. This step is a hallmark of expert financial modelers and ensures that the model is well-structured and suited to its purpose​​.
  2. Documenting Assumptions and Logic: It's important to document all assumptions and the logic behind them. This can involve using specific colors or notes in the model to indicate inputs and assumptions. Such documentation helps users understand the rationale behind the model and ensures transparency​​.
  3. Simplifying the Model: Avoid overcomplicating the model with unnecessary inputs or complex macros. The use of macros should be minimized to the barest minimum to maintain simplicity and clarity. Unnecessary inputs that are not used for any calculation should be removed to avoid clutter and confusion​​.
  4. Avoiding Hard Coding: Instead of embedding constants directly in formulas (hard coding), inputs should be placed in an input sheet. This approach enhances the flexibility of the model and makes it easier to update and adjust as needed​​.
  5. Incorporating Error Checks and Validation: Building error checks into the model, such as balance checks and solvency checks, is crucial. These mechanisms help to identify and correct mistakes, ensuring the accuracy and reliability of the model​​.

These practices are essential for creating robust, reliable, and user-friendly financial models.


Adhering to the FAST Standard in Financial Modeling

The FAST standard, a beacon in financial modeling, comprises four principles:

  1. F - Flexibility: A financial model must be adaptable and expandable, capable of integrating new data and adjusting to evolving requirements to maintain its relevance and utility.
  2. A - Appropriateness: Your financial model should match its intended purpose in complexity and detail, fitting the user's needs and decision-making processes without being overly intricate for simpler tasks.
  3. S  -  Structured: A financial model should be clearly and logically organized, enhancing its ease of understanding, auditing, and modification.
  4. T   -   Transparent: Ensure your financial model is designed with clear and understandable assumptions, inputs, and calculations, accessible even to those who didn't create it.
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The Quintessence of Financial Modeling

Peter encapsulates financial modeling as a tool for forecasting and decision-making. It integrates historical data and macroeconomic trends to predict future business scenarios. With financial modeling becoming an indispensable tool in executive decision-making, its accuracy and reliability are paramount.


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Meet the Presenter: Peter Ojo

Peter Ojo, the webinar's presenter, serves as an analyst and corporate trainer at dbrown Consulting, bringing a wealth of experience in financial modeling through his work on and review of numerous models. Passionate about macroeconomics, finance, financial analysis, and reporting, Peter also displays a keen interest in the intersection of artificial intelligence (AI) with finance.



This webinar by Peter Ojo is a treasure trove of insights for anyone involved in financial modeling. It underlines the need for meticulousness, clarity, and foresight in building financial models, ensuring they serve as reliable guides in the complex world of finance.

Optimizing your approach to financial modeling? Stay updated with industry best practices and enhance your financial acumen by following our blog for more insights and expert advice!

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