Globalization, rapid technological progress, and growing product variety expose manufacturing systems to increasingly volatile and uncertain production requirements. To remain competitive, manufacturing systems must be able to adapt to these changes. A critical step towards achieving manufacturing adaptability is the identification of the required levels and types of adaptability. However, the literature lacks structured methodologies to support this process, limiting effective implementation in practice. This paper addresses this methodological gap by developing an integrated framework that unifies flexibility- and reconfigurability-oriented research streams. First, a new theoretical perspective on manufacturing adaptability is proposed, encompassing newly defined concepts and terminology. Building on this foundation, the study develops a methodological framework to support manufacturers in systematically identifying adaptability requirements. The proposed method employs a scenario-based approach to account for both expected volatility and uncertainty of predictions. The framework is applied in a case study in the food processing industry and subsequently evaluated through a series of expert interviews. Results indicate that the framework has the potential to facilitate structured requirement formulation and provides practical guidance for decision-making at both strategic and operational levels. This work contributes both theoretically, by advancing a unified perspective on manufacturing adaptability, and practically, by offering a tool to operationalize the identification of adaptability requirements.