From Quantity-Based to Capacity-Aware Planning: Building Workload Control Readiness in a High-Variety Engineer-to-Order Manufacturer

High-variety engineer-to-order (ETO) manufacturers often rely on quantity-based planning logic, in which planned output is weakly connected to finite machine and labor capacity. This disconnect can create workload peaks, congested queues, and delivery unreliability. Workload Control (WLC) offers a capacity-aware planning logic for ETO environments, but its implementation depends on informational conditions that many firms do not initially possess, including order traceability, production time data, capacity visibility, and data-quality control. Although WLC research has demonstrated its potential through analytical and simulation-based studies, empirical and longitudinal evidence on how firms build these preconditions remains limited. This paper investigates how WLC informational readiness is progressively developed in practice. Based on an action-learning-informed longitudinal case study in the shaft department of a European manufacturer of customized complex electrical machines, the study identifies four cumulative readiness stages: diagnosing the planning problem, establishing order traceability and performance visibility, building capacity visibility, and addressing the data-quality layer. The findings show how technical data infrastructure and organizational routines jointly support the transition from quantity-based planning toward capacity-aware planning. The paper contributes a practice-grounded process model of WLC informational readiness by shifting attention from the design of WLC mechanisms to the informational and organizational conditions required before such mechanisms can operate reliably. For practice, it offers a case-derived staged roadmap for manufacturers that cannot move directly from quantity-based planning to full WLC implementation.