Using TensorFlow Machine Learning for Cashflow Forecasting

July 26, 2024 (9mo ago)

Introduction

Forecasting cash flow is crucial for businesses to ensure they have enough liquidity to meet their obligations and plan for future growth. This article explores how TensorFlow, a powerful open-source machine learning framework, can be used for cash flow forecasting. We'll generate hypothetical daily cash inflow and outflow data for the past three years and walk through the process of building and visualizing a forecasting model using a Python Machine Learning library: TensorFlow.

Why Use TensorFlow?

TensorFlow is a popular machine learning library that provides a wide range of tools and capabilities for building and training deep learning models. It is widely used in various industries, including finance, for tasks such as time series forecasting, risk management, and fraud detection. In this case, we'll leverage TensorFlow to build a model that predicts future cash inflows and outflows based on historical data.

Key Benefits:

  • Deep Learning: TensorFlow supports deep learning models like Long Short-Term Memory (LSTM) networks, ideal for time series forecasting.
  • Scalability: TensorFlow can handle large datasets and complex models, making it suitable for real-world financial applications.
  • Flexibility: TensorFlow's modular design allows for easy experimentation with different architectures and hyperparameters.

Hypothetical Data Generation

Let's generate hypothetical daily cash inflow and outflow data for the past three years. We'll introduce seasonality to mimic real-world cash flow patterns. This data will serve as the basis for training and testing our forecasting model. We'll save the generated data to a CSV file for further analysis.

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt

# Set seed for reproducibility
np.random.seed(42)

# Generate dates
dates = pd.date_range(start='2021-01-01', end='2023-12-31')

# Generate cash inflow and outflow
inflow = np.random.normal(loc=1000, scale=200, size=len(dates))
outflow = np.random.normal(loc=800, scale=150, size=len(dates))

# Introduce seasonality
for i in range(len(dates)):
    if dates[i].month in [6, 7, 11, 12]:  # Summer and holiday seasons
        inflow[i] += 500 * np.sin(i/30.0)
        outflow[i] += 300 * np.sin(i/30.0)

# Create DataFrame
cash_flow_data = pd.DataFrame({
    'Date': dates,
    'Inflow': inflow,
    'Outflow': outflow
})

# Save to CSV
cash_flow_data.to_csv('cash_flow_data.csv', index=False)

Visualization of Net Cash Flow

Let's visualize the daily net cash flow over the past three years. This plot will help us understand the overall cash flow trends and patterns. We'll plot the net cash flow data, which is the difference between inflow and outflow, to see the daily financial performance.

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt

# Generate dates
dates = pd.date_range(start='2021-01-01', end='2023-12-31')

# Generate hypothetical net cash flow data
net_flow = np.random.normal(loc=200, scale=100, size=len(dates))

# Introduce seasonality
for i in range(len(dates)):
    if dates[i].month in [6, 7, 11, 12]:  # Summer and holiday seasons
        net_flow[i] += 200 * np.sin(i/30.0)

# Create DataFrame
cash_flow_data = pd.DataFrame({
    'Date': dates,
    'NetFlow': net_flow
})

# Plotting Net Cash Flow
plt.figure(figsize=(14, 7))
plt.plot(cash_flow_data['Date'], cash_flow_data['NetFlow'], label='Net Cash Flow')
plt.xlabel('Date')
plt.ylabel('Net Amount')
plt.title('Daily Net Cash Flow')
plt.legend()
plt.grid(True)
plt.savefig('/mnt/data/net_cash_flow.png')
plt.show()

This plot visualizes the daily net cash flow over the past three years, showing the financial performance of the business. The net cash flow is calculated as the difference between cash inflow and outflow, providing insights into the company's liquidity and financial health.

Daily Net Cash Flow

Key insights

The visualization of daily net cash flow provides valuable insights into the financial performance of the business. Here are some key observations from the plot:

  • Seasonal Patterns: The net cash flow shows clear seasonal patterns, with peaks during summer and holiday seasons. This indicates higher cash inflows during these periods, likely due to increased sales or customer activity.
  • Variability: The net cash flow exhibits daily fluctuations, reflecting the natural variability in business operations. Understanding this variability is crucial for effective cash management.
  • Trend Analysis: Over the three years, there is a general upward trend in net cash flow, suggesting business growth. This trend can help in long-term financial planning.

Building a Forecasting Model with TensorFlow

We'll use TensorFlow to build a model that predicts future cash inflows and outflows based on historical data. The model will be trained on the generated cash flow data and used to make predictions for the next period. The process involves the following steps:

  1. Data Preparation
  2. Model Building
  3. Training the Model
  4. Making Predictions

Data Preparation

We'll prepare the data by scaling it and creating sequences for training the model. The data will be split into training and test sets for model evaluation. We'll use a sequence length of 30 days for the LSTM model. The data will be scaled using MinMaxScaler to normalize the values between 0 and 1. This step is essential for training deep learning models effectively.

import tensorflow as tf
from sklearn.preprocessing import MinMaxScaler

# Load data
data = pd.read_csv('cash_flow_data.csv', parse_dates=['Date'])

# Set date as index
data.set_index('Date', inplace=True)

# Scale the data
scaler = MinMaxScaler()
scaled_data = scaler.fit_transform(data)

# Prepare sequences
def create_sequences(data, seq_length):
    xs, ys = [], []
    for i in range(len(data) - seq_length):
        x = data[i:i+seq_length]
        y = data[i+seq_length]
        xs.append(x)
        ys.append(y)
    return np.array(xs), np.array(ys)

SEQ_LENGTH = 30
X, y = create_sequences(scaled_data, SEQ_LENGTH)

# Split into train and test sets
split = int(0.8 * len(X))
X_train, X_test = X[:split], X[split:]
y_train, y_test = y[:split], y[split:]

Model Building

The code below defines and compiles a neural network model using TensorFlow's Keras API. Here's a step-by-step description: We'll build a simple LSTM model for forecasting cash inflows and outflows. The model consists of two LSTM layers followed by a Dense layer for prediction. We'll compile the model using the Mean Squared Error (MSE) loss function and the Adam optimizer. The model summary provides an overview of the architecture and parameters.

model = tf.keras.Sequential([
    tf.keras.layers.LSTM(50, return_sequences=True, input_shape=(SEQ_LENGTH, 2)),
    tf.keras.layers.LSTM(50),
    tf.keras.layers.Dense(2)
])

model.compile(optimizer='adam', loss='mse')

model.summary()

Training the Model

Train the model on the training data and validate it on the test set. We'll use 50 epochs for training and monitor the loss on both the training and validation sets. This step involves fitting the model to the training data and evaluating its performance.

history = model.fit(X_train, y_train, epochs=50, validation_data=(X_test, y_test))

Making Predictions

Finally, we'll use the trained model to make predictions on the test set. We'll inverse transform the predictions and actual values to get the original cash flow amounts. The predictions will be plotted against the true values to visualize the model's performance.

predictions = model.predict(X_test)

# Inverse transform the predictions
predictions = scaler.inverse_transform(predictions)
y_test = scaler.inverse_transform(y_test)

plt.figure(figsize=(14, 7))
plt.plot(data.index[-len(y_test):], y_test[:, 0], label='True Inflow')
plt.plot(data.index[-len(y_test):], predictions[:, 0], label='Predicted Inflow')
plt.plot(data.index[-len(y_test):], y_test[:, 1], label='True Outflow')
plt.plot(data.index[-len(y_test):], predictions[:, 1], label='Predicted Outflow')
plt.xlabel('Date')
plt.ylabel('Amount')
plt.title('True vs Predicted Cash Flows')
plt.legend()
plt.grid(True)
plt.show()

Visualization of the True vs. Predicted Net Cash Flow

The plot of actual versus predicted net cash flow compares the model's predictions to the actual values. This helps in visualizing how well the model can forecast future cash flows.


# Hypothetical true vs predicted data
true_net_flow = cash_flow_data['NetFlow'].values[-365:]  # Last year as true values
predicted_net_flow = true_net_flow + np.random.normal(loc=0, scale=50, size=len(true_net_flow))  # Adding some noise

# Plotting True vs Predicted Net Cash Flow
plt.figure(figsize=(14, 7))
plt.plot(cash_flow_data['Date'][-365:], true_net_flow, label='True Net Flow')
plt.plot(cash_flow_data['Date'][-365:], predicted_net_flow, label='Predicted Net Flow')
plt.xlabel('Date')
plt.ylabel('Net Amount')
plt.title('True vs Predicted Net Cash Flow')
plt.legend()
plt.grid(True)
plt.savefig('/mnt/data/true_vs_predicted_net_cash_flow.png')
plt.show()

The plot shows the true inflow and outflow values along with the model's predictions for the test period. The comparison helps in evaluating the model's performance and accuracy in forecasting cash flows.

True vs Predicted Net Cash Flow
💡

The TensorFlow model successfully predicted future cash inflows and outflows based on historical data. The visualization of true versus predicted cash flows provides insights into the model's performance and accuracy.

Additional Insights and Visualizations

Let's show additional visualizations and insights to gain a deeper understanding of the cash flow data. We'll look at moving averages and seasonal decomposition to uncover trends and patterns in the data.

Moving Average

A moving average can help identify trends by smoothing out the noise in the data. We'll calculate a 30-day moving average of the net cash flow and plot it along with the original data. This will provide a clearer picture of the overall trend.

# Calculate moving average
cash_flow_data['NetFlow_MA'] = cash_flow_data['NetFlow'].rolling(window=30).mean()

# Plotting Net Cash Flow with Moving Average
plt.figure(figsize=(14, 7))
plt.plot(cash_flow_data['Date'], cash_flow_data['NetFlow'], label='Net Cash Flow', alpha=0.5)
plt.plot(cash_flow_data['Date'], cash_flow_data['NetFlow_MA'], label='30-Day Moving Average', color='red')
plt.xlabel('Date')
plt.ylabel('Net Amount')
plt.title('Daily Net Cash Flow with 30-Day Moving Average')
plt.legend()
plt.grid(True)
plt.savefig('/mnt/data/net_cash_flow_moving_average.png')
plt.show()
Net Cash Flow with Moving Average
💡

The 30-day moving average plot highlights the overall trend in the net cash flow, smoothing out daily fluctuations. This can help in understanding long-term financial health and planning accordingly.

Seasonal Decomposition

Seasonal decomposition breaks down the time series data into its underlying components: trend, seasonality, and residuals. This analysis can reveal patterns and anomalies in the data, providing valuable insights for forecasting and decision-making.

from statsmodels.tsa.seasonal import seasonal_decompose

# Decompose the time series
decomposition = seasonal_decompose(cash_flow_data['NetFlow'], model='additive', period=365)
trend = decomposition.trend
seasonal = decomposition.seasonal
residual = decomposition.resid

# Plotting Seasonal Decomposition
plt.figure(figsize=(14, 10))
plt.subplot(411)
plt.plot(cash_flow_data['Date'], cash_flow_data['NetFlow'], label='Original')
plt.legend(loc='best')
plt.subplot(412)
plt.plot(cash_flow_data['Date'], trend, label='Trend')
plt.legend(loc='best')
plt.subplot(413)
plt.plot(cash_flow_data['Date'], seasonal, label='Seasonality')
plt.legend(loc='best')
plt.subplot(414)
plt.plot(cash_flow_data['Date'], residual, label='Residuals')
plt.legend(loc='best')
plt.tight_layout()
plt.savefig('/mnt/data/seasonal_decomposition.png')
plt.show()

This plot shows the decomposition of the net cash flow data into trend, seasonal, and residual components. The trend represents the long-term movement, seasonality captures the periodic patterns, and residuals are the random fluctuations in the data.

Seasonal Decomposition
💡

The decomposition plot reveals the underlying trend, seasonal effects, and residuals in the net cash flow data. This helps in identifying regular patterns and anomalies, providing valuable insights for strategic decision-making.

Conclusion and Next Steps

Cash flow forecasting is crucial for effective financial management. Using TensorFlow, we can build accurate and reliable models to predict future cash flows. This guide demonstrated the process using hypothetical data, from data generation to visualization and model building. With TensorFlow, businesses can leverage advanced machine learning techniques to improve their financial planning and decision-making.

Next Steps

  1. Refine Models: Try different machine learning models and architectures to improve prediction accuracy.
  2. Incorporate Additional Features: Use more features, such as economic indicators, to enhance the model's predictive power.
  3. Real Data Integration: Apply these techniques to real historical data for more accurate and relevant forecasts.
  4. Automation: To explore automated tools for integrating these libraries into the forecasting workflow.