IT products and services are designed to address customer problems and needs. In some cases, a specific need is common to all customers and can be resolved with a particular solution. However, there are problem domains where a one-size-fits-all solution is not feasible and cannot be easily addressed by generic software offerings. In such scenarios, customers are underserved or must manage highly complex variations and configurations of IT solutions to tailor them to their needs, as seen with expert systems. The IT solution in these cases dictates what can and cannot be customized. Typically, products or SaaS solutions guide customers along a predefined path, offering feature packages such as free or professional versions. Generative products, however, place the customer in control, enabling them to adapt the IT product or service to create a personalized solution that meets their specific needs, surpassing predefined options and configuration variations of expert systems. This paper proposes an approach to designing generative IT solutions and demonstrates its effectiveness through a case study. The approach aims to address both fit-for-purpose and fit-for-use considerations by incorporating quality aspects. The case study presents as an example a Volkswagen Group IT SaaS solution that was extended to become a generative IT product, providing a tailored and individualized solution from the user's perspective.