System Dynamics methodology
Supply chain systems have a dynamic characteristic because of uncertainties in demand, supply, and various logistics methods. Recently, with increasing complexity of supply chain dynamics using system dynamics modeling has become popular (
27). As SD models are based on feedback models, causal loop diagrams (CLD) were provided to explain intrinsic feedback of activities. “The feedback loop when a change in something ultimately comes back to cause a further change in the same thing” (
28).
Qualitative system dynamics based on causal loops
Many authors suggested that CLDs could be used as a conceptual model and help to structure and solve managerial problems (
29-
31). With the progression of this concept, two parallel methods were formed. The first concept which is termed "
qualitative system dynamics" was intended to apply all phases of system dynamics besides quantification modeling. The idea of setting up model boundaries has specified responsibilities of managers to prospect how processes might be interacted. Furthermore, it could be combined in to most simulation packages (
32). The second concept of CLDs was made as an important part of organizational learning which is named "system thinking". Also, this idea has made managerial perception about the system behavior by concluding, rather than calculating (
28). Visualizing dynamic problems with CLDs is an ideal way to bring the decision points and performance measures to the managers’ attention (
33).
System Dynamics modeling processes
The standard system dynamics method based on Sterman definition is the sequence of activities to study a particular problem (
30). These steps are problem definition, dynamic hypothesis, formulation, testing, policy formulation and evaluation. The SD method is used here to take into consideration all variables in terms of both systemic approaches to the variables interactions and flows, and managerial perspective.
This study tries to explore the pharmaceutical manufacturing supply chain challenges in Iran and find out the relationship between variables affecting these problems by the first two steps of SD method, problem definition, and causal loop diagram. The model provided below is a qualitative model based on extensive literature review and semi-structured interview with experts on pharmaceutical supply chain.
Based on the findings, there are several serious challenges in Iran pharmaceutical industry which have an influence on the competitiveness, profitability, and overall supply chain performance in both external and internal organizations environment. Macro environment troubles include macroeconomics and political situation like sanctions, exchange rate fluctuation, financing issues, lake of proper infrastructure, counterfeit drugs, and lake of transparency and unpredictability of shifts in government economic policies, and highly regulated nature of this business. On the other hand, lack of integration and collaboration between different echelons of supply chain, lack of information visibility, transparency and sharing, high rate of obsolescence machinery, costly and time consuming R and D processes, restricted pricing policy affecting the competitiveness and quality of products, uncertainty in supplying qualified raw materials in their respective required quantity and at the right time lack of effective supplier relationship management are just a number of inter organization problems.
Problem definition (Boundary Issues)
The extent of the model must be defined in any kind of modeling. Conscious decision must be made to clarify where the boundaries of the model are. Otherwise, developing a system model could be ultimately endless.
Therefore, the first part of the research was undertaken by Semi-structured face to face interviews with 25 expert managers from different pharmaceutical manufacturing companies who have at least 5 year responsibilities in any parts of the supply chain, including marketing, planning, commercial, manufacturing, sales, and financing for clarifying pharmaceutical supply chain structure and model boundaries, as well as their challenges related to SCM.
To address these goals, the interview questions were developed and guided by the wide-ranging literature review and the five main SCOR performance attributes and their associated level 1 metrics (
34,
35)
Table 1 represents the five performance attributes used within the SCOR model and the associated thirteen level one metrics.
The interviewees were asked to explain the supply chain structure and processes in their companies and specify the challenges which can cause difficulty in achieving supply chain goals, considering SCOR performance attributes. In addition, the interviewees were given the opportunity to add any other challenges that they believed were relevant for their particular operation. The interviews were recorded digitally and the notes were taken during the interviews.
The model boundaries and variables included in each sector of the CLDs were based on the notes taken and the audio recordings of interviews.
Figure 1 shows the market oriented pharmaceutical supply chain and model boundaries.
In brief explanation, in this industry, the SC Processes initiate by product development and marketing activities as a strategic function. This means that the sales and marketing unit try to find the market needs and change them to demands. They achieve their goals by communicating with physicians authorized to prescribe pharmaceutical products to end users. On the other hand, sales and marketing unit interacts with distribution companies and pharmacies to sell their products. In this way, they can monitor the market as downstream and forecast future demand. Marketing department provides forecast information for planning department to schedule all internal processes including purchasing materials, formulation and making finished products, and distribution in response to market demand. The branded-generic pharmaceutical manufacturing companies also have upstream companies which may have local or international activities, to supply active pharmaceutical ingredients and other inactive materials. Therefore, the supplier selection and supplier relationship are critical tasks for manufacturing companies, they have to evaluated suppliers considering both qualitative and quantitative factors such as quality of materials, delivery performance, their reputation and position in industry, bargaining power, production facilities and capacity, technical capability, geographic location, order fulfillment lead time, net price, total logistics cost etc. (
36).
With these descriptions, the model boundaries of this research has determined all challenges related to pharmaceutical manufacturing company processes which can affect them and have ability to improve the processes by changing the policies and decisions. All other concerns related to entities in up and down stream of manufacturer are placed beyond the study boundaries.
Dynamic hypothesis
Based on the interviews, the supply chain challenges of pharmaceutical manufacturing companies are identified and listed in accordance with SCOR model attributes in
Table 2.
The basic CLDs of market oriented PSC was developed based on literature review and expert opinions.
Figure 2 shows the basic relationship between variables playing a role in the pharmaceutical supply chain.
In general, the most important goal of a profit-seeking companies is to maximize stockholder value which can be divided into three sub-objectives including profitability, survival and continuous in existence, and growth. To achieve them, companies must improve financial performance such as - revenue, return on investment, and cash flow - as well as non-financial performance such as - market share, customer satisfaction, number of new products development, and number of employees.
In market oriented pharmaceutical manufacturing companies, all processes start with product development and marketing activities via market research and analysis to find unmet health needs and create demands through promotional actions to introduce products to the health care professionals. On the other hand, the marketing units can calculate the sales forecasts by observing the market and providing it to planning unit to project the production schedule and finished products inventory in accordance to market demands. The appropriate production inventory can increase the distributors’ warehouses inventory and the orders will be fulfilled completely. At this point, the actual sales can be recorded for manufacturing companies; however, the invoices will be paid with a delay of several months. Increasing actual sales leads to more revenue and profit. On the other hand, market share will be also increased. Ultimately, the marketing departments can benefit from profit to increase marketing promotions to boost demands. There is one subtractive loop to balance the two others reinforcing ones. If the production inventory is not enough to meet the market demands, the distributors could not fulfill orders. By declining order fulfillment rate, shortage and sales loss will occur; as a result, actual sales will decrease. Based on the SCM experts opinions supported by literature, Inaccuracy or anomaly in sales forecast calculating and production capacity limitations can be considered as the causes of inadequate production inventories.
On the other hand, two balancing loops can be added to explain the processes of creating product inventory. As noted earlier, material purchasing plan as well as production plan will be conducted based on sales forecasting. The procurement departments prepare raw materials needed from several supplier companies. There are several factors affecting supply performance of such supplier’s ability to cover orders in terms of quality and quantity of raw materials, cost of raw material and shipment, and delivery time. The material inventory and products inventory have a moderating effect on ordering rate (
Figure 3).
As experts asserted in Iran pharma industry, financial and political issues cause some limitations for supplying APIs especially for imported materials. Also, a lack of collaborative relationship strategies with suppliers can create harder condition for pharmaceutical manufacturing companies such as deviation of forecasts, drastic inventory oscillations, and stock-out episodes. Therefore, they buffer a large amount of materials and products inventory. Although, this strategy enhances responsiveness, increases customer satisfaction, and decreases sales loss, it can cause other problems such as the need for more warehouse space and their management, increasing inventory costs, and the risk of material or product expiration (
Figure 4).
The other major problem in this business is long lead times including time for new product development, capacity acquisition, procurement, production, distribution, regulatory process, and cash to cash cycle time. The long lead times prevent PSC abilities to be reliable and responsive. This property not only can degrade PSC agility and market share; but, may increase overall costs as well. While, to remain competitive, these firms must reduce costs whereas continuously improve responsiveness.
After expressing the PSC problems, the dynamic hypotheses are developed. Major challenges which can affect both effectiveness and efficiency of PSC can be briefly summarized as follows: inaccuracy in forecasting, long lead times, lack of optimum target inventory, and high SC costs.
With such problems, achieving profitability, customer satisfaction, as well as market share would not be possible. There are several improving actions and correcting decisions that have already been experienced in other industries and many researches have showed their effectiveness, and they can be used to overcome these challenges. In the following section, the impact of some of the suggested policies will be discussed on the causal loop model.
Since system dynamics modeling is the interactive process between researchers and participants (manager, owners and associated actors) of problem situation who are experts in their field, after developing the causal loop diagrams the validity of relationship between variables were verified by those pharmaceutical supply chain experts who were participated in the interviews. Then, the suggested policies to mitigate the SC problems were implemented in model and confirmed by them (37, 38). In the next step, the effects of suggested polices were discussed.