Case 02Customer Analytics · Strategy

Telecom Customer Churn Analysis

Analyzed 7,043 telecom customer records and used explainable classification models to identify churn-risk segments and propose targeted retention actions.

Period · Summer 2025

Role · Individual project · KW-Corporation university virtual-company program

Source · GitHub repository

Quick read

The through-line of the work.

Open

The starting question

From the start, the focus was less on producing a churn-prediction score and more on finding risk signals that sales and marketing could read straight away.

Build

What I checked

I looked at churn rates and model output together, anchored on the traces customers actually leave behind: contract type, tenure, monthly charge, and payment method.

Turn

What changed my view

The strongest signal was month-to-month contracts, with short tenure and high monthly charges moving in the same direction.

Close

Where I draw the line

The 5.0-percentage-point reduction, though, is a target set before any rollout. I kept it as a proposal still to be tested, not something to present as a result.

01 · Start

The question I began with

Which customers are most likely to leave, why are they at risk, and which retention response fits each segment?

02 · Material

The data and evidence

7,043 customer records across profile, contract, tenure, billing, payment, service, and churn fields
70/30 train-test split and seven classification models
Model evaluation using ROC-AUC, precision, recall, and F1-score
Pythonpandasscikit-learnGradient BoostingXGBoostSHAP

03 · Work

How I worked through it

  1. 01

    Prepare the evidence

    Converted blank TotalCharges entries, encoded categorical variables, and created analysis-ready training and test sets.

  2. 02

    Find meaningful segments

    Examined churn patterns across contract type, tenure, monthly charges, payment method, and service adoption.

  3. 03

    Compare and interpret models

    Compared seven classifiers, selected Gradient Boosting on the strongest ROC-AUC, and used SHAP and dependence analysis to explain key drivers.

  4. 04

    Translate analysis into action

    Connected risk drivers to proposed contract, onboarding, and service-support interventions.

04 · Takeaway

What the numbers suggested

Month-to-month contracts were the clearest churn-risk signal.

Shorter tenure and higher monthly charges were associated with greater risk.

Non-use of selected security and technical-support services provided additional risk signals.

Gradient Boosting reaches a test-set ROC-AUC of 0.841, and reproduce.py in the repository regenerates the same metrics table.

Not claimed

  • Does not claim churn fell by 5.0 percentage points. It is a pre-execution target still to be tested.
  • Does not read SHAP as causal. It explains how the model decided, nothing more.
  • Does not claim a real retention outcome. The public dataset carries no intervention results.
Important boundary: The 5.0 percentage-point churn reduction is a proposed planning target, not an achieved business result.

05 · Use

Where this helps

The analysis turns a binary prediction task into a prioritization framework and proposes retention strategies targeting a 5.0 percentage-point reduction in churn; the target has not been achieved or validated.

06 · Boundary

What still needs checking

  • •The dataset is public and does not include campaign exposure, complaint history, intervention cost, or observed retention outcomes.
  • •The final model pipeline, hyperparameters, random seed, and metrics table should be reproduced before treating the exact score as verified.
  • •Proposed interventions require experimental validation and explicit retention KPIs.

07 · Figures

Tables and figures

Churn rate by contract type

Verified source
Month-to-month42.71%
One year11.27%
Two year2.83%

Calculated directly from the source CSV. The bars show a descriptive association between contract type and churn; they do not show that an intervention reduced churn.

Source · WA_Fn-UseC_-Telco-Customer-Churn.csv · 7,043 rows

Churn rate by tenure group

Verified source
0–12 months47.44% · n=2,186
13–24 months28.71% · n=1,024
25–48 months20.39% · n=1,594
49–72 months9.51% · n=2,239

Tenure was grouped into four intervals directly from the CSV. The chart describes higher churn among newer customers; it does not identify individual causation or validate a proposed retention action.

Source · WA_Fn-UseC_-Telco-Customer-Churn.csv · bins computed from tenure