Developing a System Dynamic Model for Product Life Cycle Management of Generic Pharmaceutical Products: Its Relation with Open Innovation

The purpose of this study is to identify elements that influence the sale of generic pharmaceutical products during their life cycle in order to achieve more comprehensive planning and to prevent a decline stage of the product life cycle (PLC). We used a system dynamic model to identify the behaviors of demand, supply, and competition as three major subsystems of PLC in generic pharmaceutical products. We first investigated the PLC patterns of 527 medicines to identify their “reference mode”, determined the causal loop of the pharmaceuticals phase of PLC based on both an in-depth literature review and experts’ opinions, and finally simulated a quantitative dynamic model based on real-world data between 2012 and 2019 from Iran. Based on the results, “total demand and accurate forecasting”, “marketing efforts”, and “R and D activities of a firm” are the most critical factors involved in the formation of a generic drug PLC. An increase of 20–50% of manufacturers’ marketing and R and D activities can raise sales by more than 50% in the decline stage of the PLC. The product life cycle can give generic manufacturers more insights into the processes leading to declining sales of their products. PLC may help to prevent a product from entering the decline stage even if the total demand for a generic drug is dropping in the market.

Research on compact propulsion system dynamic model based on deep neural network

The on-board dynamic model is the basis of numerous advanced control technologies for modern aero-engine, and its accuracy and real-time performance are two crucial indicators. Since the simulation accuracy declines with the deviation from the ground point of the conventional compact propulsion system dynamic model (CPSDM), an improved CPSDM (ICPSDM) based on deep neural network is proposed in this paper. First, the K-means algorithm is utilized to get the sampling point, and the engine simulation data is collected in the cluster centers. Then, the batch normalize deep neural network (BN-DNN) is applied to build the ICPSDM, which can shorten the training time tremendously. The simulation results show that, in the same simulation environment, the accuracy of turbine inlet temperature T 4 , fan surge margin SMc, thrust F, and specific fuel consumption SFC calculated by ICPSDM are 11.04, 3.17, 1.89, and 1.98 times of CPSDM, respectively, at off-design point, and the real-time performance of ICPSDM is more than 30 times faster than the component-level model.

System-dynamic model of power redistribution among several subjects

A simple model simulating the redistribution of decision-making functions between the state, business, bureaucracy and regional elites is presented. The methodological basis of the work is system-dynamic modeling. The model is implemented in the specialized program Powersim Studio 10. A diagram of stocks and flows is considered, all elements of which were compared with certain political science concepts. The mathematical apparatus of the model is described. Some results of computer experiments are presented: these results indicate the operability and interpretability of the model.

A system dynamic model to quantify the impacts of water resources allocation on water-energy-food-society (WEFS) nexus

Sustainable management of water-energy-food (WEF) nexus remains an urgent challenge, as interactions between WEF and community sensitivity and reservoir operation in water system are often neglected. This paper aims to provide a new approach for modeling WEF nexus by incorporating community sensitivity and reservoirs operation into the system. The co-evolution behaviors of the nexus across water, energy, food and society (WEFS) were simulated by the system dynamic model. The reservoirs operation was simulated to determine water supply for energy and food systems by the Interactive River-Aquifer Simulation water resources allocations model. Shortage rates for water, energy and food resulted from the simulations were used to qualify their impacts on WEFS nexus through environmental awareness (EA) in society system. Community sensitivity indicated by EA can adjust the co-evolution behaviors of WEFS nexus through feedback loops. The proposed approach was applied to the mid-lower reaches of Hanjiang river basin in China as a case study. Results show that EA accumulation is mainly from shortages of water and energy, and the available water and energy are the vital resources to sustain WEFS nexus. Feedback driven by EA effectively keeps the system from collapsing and contributes to the concordant development of WEFS nexus. Water resources allocation can remarkably ensure water supply through reservoirs operation, decreasing water shortage rate from 16.60 % to 7.53 %. The resource constraining the WEFS nexus is transferred from water to energy. This paper therefore contributes to the understanding of interactions across WEFS system and helps the efficiency improving of resources management.

CASE STUDY: DESIGN VALUE MEASURING BY SYSTEM DYNAMICS

The aim of the article is to show a way to measure the economic value of design using system dynamic modeling of key processes in an organization. The article fully accepts the complexity of the concept of design and opens up the possibility for employing system dynamics in design value measuring. The definition of design is given as an integral concept for which it is difficult to find a benchmark. The sequential explanatory method was chosen to solve the research problem. Qualitative data is collected first and it is recorded and examined. After that the data is transformed into numeric values and taken for quantitative evaluation in a system dynamic model. The connection of qualitative research data in a tool for quantitative evaluation allows an original interpretation of relationships that have been obtained and are collected only as qualitative data. Qualitative data collection is based on the visualization of a new definition of design: Design is an integration of functional, distribution, emotional and social experience of the customer. The questionnaire is in the form of Design Value Canvas and is used to determine the initial Design Value Algorithm (DVA) coefficient. As an external parameter, the DVA coefficient influences the development of the number of customers and their willingness to order the company’s products in the system dynamic model. The main result is the finding that an investment in design, which is confronted with customer preferences, fundamentally changes the economic parameters of business. Economic benefits of a design change in a company are always influenced by a strategic decision made by the entrepreneur who has to know the behaviour of their customers and to correctly choose the field of design in which it pays to invest.

A System Dynamic Model of Water-Land-Food-Energy-Ecosystem-Environment-Economic-Social Nexus for Western Lake Erie Basin-USA

The concept of water-food-energy nexus has been widely studied in the past decade. In this paper we expand on this concept to Water-Food-Land-Energy-Ecosystem-Environment Nexus with economic and social aspects based on the life cycle assessment thinking. Set of Environment Footprint Assessment (EFA), Life Cycle Assessment (LCA), and Socio-Economic Assessment (SEA) indicators are proposed to apply this approach. Decision Support System for Water-Land-Food-Energy-Ecosystem-Environment-Economic-Social nexus (SD-WLF4ES-Nexus) applying system dynamic model approach for simulating this tackle is utilized. SD-WLF4ES-Nexus is applied to predict the WLF4ES nexus of one of the main crop, corn crop, in twenty counties located in Western Lake Erie Basin (WLEB) in USA for the period 2016-2030. The prediction is based on scenarios for population, planted and harvested land, and yield, crop production use by segments, and crop production costs and returns. A matrix for WLF4ES nexus of corn crop in WLEB is developed. This matrix can help in developing polices and strategies for managing the nexus in the basin.