What is the CSI (Customer Satisfaction Index)? – A Guide

What is CSI?

CSI, or Customer Satisfaction Index, is an internationally established and standardised method for measuring customer satisfaction. It is used to understand how satisfied customers are with a business and which aspects of the business affect their experience the most. By using CSI measurement, companies can gain insight into customers’ expectations, experiences, and loyalty – important factors for improving both the business and the relationship with customers.

A CSI value is usually based on three core questions asked to customers:

How satisfied are you with the business as a whole?
How well has the business met your expectations?
How close or far from your ideal do you consider the business to have been?

These questions are answered on a ten-point scale and are then converted into an index from 0–100, where higher values indicate higher customer satisfaction. Generally, a CSI value between 65 and 75 is considered ”average satisfaction,” while higher values indicate exceptional customer satisfaction.

How CSI can be used

A CSI survey is an important part of a business’s work to improve its customer satisfaction. By measuring the Customer Satisfaction Index, companies can identify both strengths and areas for improvement, and thereby prioritise the right initiatives to meet customers’ needs.

Here are some common ways to use CSI:

Understand customer experiences: CSI helps to measure and analyse how customers perceive the quality of products, services, and customer support.
Identify areas for improvement: By seeing which areas have lower ratings, companies can direct their resources to make strategic improvements.
Benchmarking: Since CSI is a standardised method, companies can compare their results with other businesses within the same industry to see how they stand against the competition.
Tracking over time: By conducting CSI measurements regularly, companies can track changes in customer satisfaction and see the effects of their improvement efforts.

How is CSI calculated?

Calculating CSI is a process that involves collecting and analysing customers’ answers to the three core questions. Here is a simplified guide on how to calculate CSI:

Collect data: The answers from each customer are given a score on a ten-point scale, where 1 means ”very dissatisfied” and 10 means ”very satisfied.”
Calculate averages: For each question, an average score is calculated based on all answers.
Create an index: The averages are then converted into an index value between 0 and 100. The formula used ensures that CSI becomes an easily understandable and comparable measure.

Example: If customers give an average rating of 8.5 on a question, it is converted into a CSI value of 85.

To create a comprehensive analysis, companies can also supplement the core questions with specific questions about, for example, value for money, product quality, or customer service. This data makes it possible to identify the drivers behind customer satisfaction.

Benefits of CSI measurement

Using CSI surveys provides several important benefits for companies that want to create a customer-centric business. Here are some of the main advantages:

Deeper customer insights: CSI gives companies a clear picture of how customers experience their business and what affects their satisfaction.
Data-based priorities: With the help of CSI measurements, companies can identify which actions have the greatest effect on customer satisfaction and prioritise these.
Opportunity for benchmarking: The standardisation of CSI makes it easy to compare the results with other companies or industries, which provides a valuable perspective.
Improve the customer experience: CSI serves as a guide for creating a better customer experience, which in turn strengthens customer relationships and loyalty.

How to improve CSI

An important part of working with CSI is using the insights to create improvements. Here are some strategies for improving CSI:

Listen to customer feedback: Identify specific problem areas based on the answers from CSI surveys. If customers complain about long waiting times in customer service, review how these can be shortened.
Increase quality: Invest in product and service development to meet and exceed customer expectations.
Train staff: Ensure that staff have the right skills and tools to provide a superior customer experience.
Communicate improvements: Show customers that you listen to their feedback and are actively working to make improvements.
Use the right tools: Effective survey tools and analysis platforms can help you collect and interpret data better, making it easier to act on the results.

Frequently Asked Questions about CSI

What is the difference between CSI, NPS, and CSAT?

It is common for these three key performance indicators to be used together, but they measure different things:

CSI (Customer Satisfaction Index): Is an index that provides an overall rating of total customer satisfaction. It is based on a standardised model with three core questions (satisfaction, expectations, ideal) and provides a deep, holistic view.
CSAT (Customer Satisfaction): Measures customer satisfaction with a specific, recently completed interaction, such as a purchase or a support case. It is a transactional and direct measure.
NPS (Net Promoter Score): Measures customer loyalty and the likelihood that a customer will recommend the company. It focuses on future behaviour and brand loyalty, not necessarily on satisfaction in the moment.

One could say that CSI provides a broad and stable temperature check on the overall relationship, while CSAT and NPS provide valuable insights into specific parts and loyalty.

How often should one measure CSI?

The frequency depends on the company’s business model and purpose. Traditionally, CSI has been measured annually to get a strategic overview and compare results over time. The modern approach often combines this with more frequent measurements:

Annual measurement: Good for overall strategic planning, benchmarking against the industry, and seeing long-term trends.
Continuous measurement: Measuring CSI (or parts of the model) at key points in the customer journey, e.g., after a completed project or 6 months after a purchase, provides more current and actionable insights.

A combination often yields the best results – an annual deep dive supplemented with more frequent pulse measurements.

What is a driver analysis in a CSI survey?

A driver analysis is one of the most valuable parts of a CSI survey. While the core questions provide an overall CSI value, supplementary questions are often asked about specific areas (e.g., product quality, customer service, value for money, delivery time). The driver analysis is a statistical method that shows which of these specific areas have the greatest impact (are the biggest drivers) on total customer satisfaction. This helps you understand why the CSI value is what it is and where you should focus your resources to get the maximum effect on customer satisfaction.

What is considered a good CSI value?

As mentioned earlier, a CSI between 65 and 75 is often considered average or ”good.” Values above 75 indicate high customer satisfaction. However, it is important to put the number in its context:

Industry differences: Some industries generally have higher CSI values than others. It is therefore most relevant to compare oneself with the average in one’s own industry.
Competitors: Knowing how your CSI stands against your direct competitors provides a clear picture of your position in the market.
Improvement over time: The most important goal is often not an absolute number, but to see a positive development of your own CSI value over time. An increase from 68 to 72 is a significant success.

Why does the CSI model use just three questions?

The model with three questions (satisfaction, expectations, ideal) is scientifically developed to create a more stable and reliable measure than a single question. The three questions capture different psychological dimensions of the customer’s experience:

Overall satisfaction: An overall, emotional assessment.
Met expectations: A more rational assessment of how well the delivery corresponded to what the customer expected.
Comparison with ideal: An assessment of how the company stands against a ”perfect” supplier, which measures potential and excellence.

By combining these three aspects, a more robust index is obtained that is less sensitive to temporary mood swings in the customer.

Customer Satisfaction Index (CSI)