## 3 Integrated SCM Model
### The Challenge of Supply Chain Bottlenecks  
A bottleneck in a supply chain is like a cog in the process, and occurs when the predecessor step is done earlier or faster than the time when the next step or operation will be used to fulfill the goal, because of poor productivity or labors or machines not performing efficiently. In this occasion, the operation lasting longer than usual is identified as the bottleneck of the supply chain management system. All the losses and inefficiencies or low speed of operating in manufacturing system are just caused by this bottleneck that negatively affects system's growth and progress to enhance the profit for manufacturing supply chain system. The managers and decision makers must identify and fix or remove the bottlenecks; that is a vital and critical issue for manufacturing supply chain processing system. For example, with using wind power generation in electricity markets, there is a bottleneck in  
Figure 2: Conceptual Model for Flow process chart of manufacturing supply chain system.  
zonal placement of spinning reserve that inhibits the deliverability of reserve that solves the increasing total cost by co-optimization model [33]. The bottleneck can be in sparking communication when there is an increase in consensus nodes that can cause problems for the large-scale applications and may increase the cost of communication. This problem and bottleneck is solved by proposing a scalable dynamic multi-agent hierarchical PBFT algorithm (SDMA-PBFT) that affects network nodes directly, from great node to the next node according to the number of nodes wrongly in the network, such as the number of consensus nodes which seriously hinder large-scale applications as multi-agent practical byzantine in permissioned block chain [34]. For example, in healthcare, where the processes are complex and multi-disciplinary in nature and have bottlenecks that are identified in two parts (pre-operative and post-operative process) resulting from the absence of certain records, staff or nature specialty, and solved by a goal-driven process evaluation method based on PM [35]. Bottlenecks may present as potential or shifting in operation mode such as rerun, low output in amount, or machine (tools) breakdowns in catastrophic events such as fire or operator carelessness that can continue manufacturing just by replacing another new machine or tool. The other, shifting type is rare to find and identify and mitigate or solve the causes [36]. In supply chain manufacturing operation system, the weakest link in entire lifecycle of a product is known as bottleneck, usually in financial problems of plant. By investigating theories on bottlenecks in supply chain network, the supply chain bottlenecks would be explored, and managers can solve the complexities by using methods such as Supply Chain Network (SCN) and Network Theory-based [37]. The results achieved the bottlenecks based on models and calculations. Since the beginning, by using the abstracted models of supply, production, and distribution individually and finally by an integrating model, a significant different in final model result is provided as well as aggregate results from Supply, Production, and Distribution (SPD) models that shows main reduction in total cost while containing quality of product [38].  
In next section, we are going to describe the supply chain models for minimizing the total cost of systems that results in finding a preventative process for bottlenecks through the multi-objective modelling of supply, production, and distribution cost models individually.