## 1 Introduction  
Businesses within supply chains often consist of different relative sizes, resulting in firms having various financial, management, knowledge, and technology capabilities and resources available to secure efficient supply chain planning [1]. These capabilities make substantial impacts on the business goals of small and medium-sized enterprises (SME) experience [2]. To investigate the origin of this key issue, ref. [3] describes the future of Enterprise resource planning systems (ERP) and the associated software complications in their comprehensive study on the practical implications of ERP systems. The authors found that digitalization will enable new opportunities for SMEs, since domain knowledge can serve as a modifier to the forecasting framework by incorporating distinctive features. In the literature on SMEs and ERP implementation, we found there are substantial barriers and challenges still remaining, and ERP implementations should not be categorized as standard IT projects [4]. Rather, an ERP implementation is an organizational change that requires interdepartmental participation across the whole organization [5]. Ref. [6] found reduced inventory to be the most common, while reduced planning, decreased lead time, and improved communication and decision-making are all established organizational gains after successful ERP implementation. Although ERP systems can impact SMEs positively, acknowledgment and awareness regarding potential implementation risks and issues associated with unsuccessful implementation must be considered. Ref. [7] identified the risks in the ERP adaptation for SMEs are mainly SMEs limited resources and their distinct operating characteristics, making the implementation case different from larger enterprises. ERP systems can adapt to manufacturing environmental changes but not uncertainty, which generally constitutes the random interventions of the real world. SMEs tend to use buffering and dampening techniques to manage the aspect of uncertainty impact with the competitive environment, strategic objective, and manufacturing structures. As a response to the standardized commercial commodity ERP software solutions, more recently, ref. [8] proposed free, open-source ERP as a framework, enabling cost-effective, customized ERP solutions for SMEs, who lack the conical capacity to invest in commercial ERP systems. Additionally, the authors argue free, open-source ERP can serve and support. Accurate demand forecast forms the backbone of supply chain planning since a forecast is a main facilitator of efficient procurement, production planning, control, and inventory management [9; 10]. Forecasts establish the operational and strategic information background that establishes the future decision-making processes of an organization. Data limitations or limited sources of historical data often prevent the application of data-driven models. To combat this issue, ref. [11] propose a set of grouping schemes based on different grouping criteria for product classification to enhance the application of machine learning models with the objective of learning future demand. However, the qualitative forecast methodology lacks a generic method approach to track the overall performance related the forecast accuracy and the potential benefits of combing the qualitative forecast with a data-driven forecast to aid the identification of trends and patterns. The forecasting inefficiency also makes a cascade effect on inventory planning. Inventory management should be assessed as an enabling competence, and in order to fully utilize the company's forecasting tools, inventory management and forecasting should be combined [12]. In practice, many SMEs reduce their competitive advantage by having inadequate inventory management.