In today's highly competitive business environment every company is heading to increase its overall production and profit by decreasing its consumed manufacturing cost. Reduction in manufacturing cost can be effectively achieved by means of reducing the non-value added costs and activities involved in the production process. Breakdown maintenance effectiveness plays a vital role in machines availability for production. Assessing breakdown maintenance activities helps an organization to organize and effectively streamline the maintenance actions carried out in order to reduce the consumption of input resources. In this research work, a method is proposed for assessing the breakdown maintenance factors using a value stream maintenance map (VSMM) enabling the assessment of measurable maintenance factors. To attain the proposed method, initially, various breakdown maintenance factors are identified and grouped. Then a breakdown maintenance performance measures hierarchy and a framework are developed in this thesis. Next a method which incorporates the calculation of key breakdown maintenance metrics and a VSMM along with the key breakdown maintenance metrics and their respective trends is detailed. Finally the proposed method is implemented in a hypothetical and three industrial case studies. This helps to record and assess the breakdown maintenance effectiveness of a production line and thus leading to continuous improvement opportunities. vi