Packaged Enterprise Systems (PES) are built with an assumption that they support best processes in the industry. Nevertheless, the PES often require some modification, often referred to as customization or configuration, to fit them with the organization and its data structures, information infrastructure, and related processes. These modifications are resource consuming and may create significant costs over the system’s lifetime, eventually generating digital debt that would lead to high risk of system failure. The organizations thus aim to modify the system as little as possible as the first measure to mitigate the risk. In this paper, we study how the organizations do this, i.e. minimize PES customization. We conducted a case study on the customization of a commercial PES in the Nordic region. We interviewed 16 business representatives and consultants involved in implementing and operating EAM system in their respective organizations. They stated in unison that modification or “customization is not good in long term.” and presented their practices of keeping customization low. Although these are not necessary “best practices”, they still provide insights into their approaches to minimize life-time costs. The interviewees shared their experiences about their mistakes, difficulties, and lessons learned. Briefly, to minimize PES customization, attention should be devoted to new product evaluation, project planning, and project execution. Different factors, such as the business process actors’ resistance to change, ineffective change management, and missing engagement of all business units, increase the amount of customization.