Get to the root of the problem by asking 5-Whys
When I want to get to the root cause of a situation I use the 5-Why technique. By repeatedly asking the question “Why” (five times is a good rule of thumb), it is possible to peel away the layers of symptoms to identify the root cause of the problem.
Why 5-Why’s? Very often the first reason for a problem will lead you to another question and then to another. Although this technique is called “5-Whys”, you may find that you will need to ask the question fewer times than five – or more than five times – before you find the issue related to a problem.
This technique works quite well to get to the root cause because with each question you’re "drilling down" to the information you really seek. So, instead of focusing the questions internally, make them customer-centric.
Here's a good example of the 5-Why technique in practice:
Marketing: The customers are not buying our products.
Marketing: Because they are buying it from our competitors.
Marketing: Because our competition has lower prices.
Marketing: Because the competition is able to make the products cheaper by reducing the cost of goods (COGS).
Marketing: Because they have eliminated a couple of features that we have in our product.
Marketing: Because apparently they are not important to our customers.
As you can see, you can get a wealth of information from almost anyone who touches the customer using this simple 5-Why technique.