In the competitive manufacturing era, agile manufacturing has evolved as a revolutionary manufacturing strategy that manages quality, innovation, responsiveness, introduction time of product, and uncertainties to maximize profit and to satisfy fluctuating demands of customers. The decision of implementing agile manufacturing is always complicated for organizations because they fear failure during the implementation process. This paper presents an innovative framework that can help decision-makers well before the implementation of agile manufacturing practices by evaluating the potential impact on an organization. The framework is based on three components, including agility cost, agility fitness, and agility outcome. The framework has been developed after intensive literature investigation, field study of manufacturing SMEs, and interviews with experts. Based on the framework, a knowledge-based system (KBS) has been developed to aid SMEs in decision-making at the implementation stage. The system is validated by case studies and by industrial experts through detailed interviews.