You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: COMBINING SYSTEM DYNAMICS AND DISCRETE EVENT SIMULATIONS - OVERVIEW OF HYBRID SIMULATION MODELS 
Chapter Title:  Scope of the hybrid model 
1. Abstract of Cited Paper (BIB001):  Hierarchical production planning provides a formal bridge between long-term plans and short-term schedules. A hybrid simulation-based production planning architecture consisting of system dynamics (SD) components at the higher decision level and discrete event simulation (DES) components at the lower decision level is presented. The need for the two types of simulation has been justified. The architecture consists of four modules: enterprise-level decision maker, SD model of enterprise, shop-level decision maker and DES model of shop. The decision makers select the optimal set of control parameters based on the estimated behavior of the system. These control parameters are used by the SD and DES models to determine the best plan based on the actual behavior of the system. High level architecture has been employed to interface SD and DES simulation models. Experimental results from a single-product manufacturing enterprise demonstrate the validity and scope of the proposed approach. 
2. Abstract of Cited Paper (BIB002):  Manufacturing enterprise decisions can be classified into four groups: business decisions, design decisions, engineering decisions, and production decisions. Numerous physical and software simulation techniques have been used to evaluate specific decisions by predicting their impact on either system performance or product performance. In this paper, we focus on the impact of production decisions, evaluated using discrete-event-simulation models, on enterprise-level performance measures. We argue that these discrete-event models alone are not enough to capture this impact. To address this problem, we propose integrating discrete-event simulation models with system dynamics models in a hybrid approach to the simulation of the entire enterprise system. This hybrid approach is conceptually consistent with current business trend toward integrated systems. We show the potentials for using this approach through an example of a semiconductor enterprise. 
3. Abstract of Cited Paper (BIB003):  The idea of combining discrete-event simulation and system dynamics has been a topic of debate in the operations research community for over a decade. Many authors have considered the potential benefits of such an approach from a methodological or practical standpoint. However, despite numerous examples of models with both discrete and continuous parameters in the computer science and engineering literature, nobody in the OR field has yet succeeded in developing a genuinely hybrid approach which truly integrates the philosophical approach and technical merits of both DES and SD in a single model. In this paper we consider some of the reasons for this and describe two practical healthcare examples of combined DES/SD models, which nevertheless fall short of the "holy grail" which has been so widely discussed in the literature over the past decade.

Literature Review:
In this section we would like to address at what scope is the hybrid model applied inside one area/organization; whether the hybrid model is about whole organization, two different functional areas inside organization, only one functional area etc. For example, the work of BIB004 has two different cases, but both use DES to simulate inner situations (hospital and calling centre operations), while SD simulates very broad scenarios (whole community or population demographics). In the case of BIB001 ) the model is a representation of a project being under away. BIB003 have modelled two different functional areas -SD for the decisions concerning allocation of the financial resources (of the plants) and DES for operational decisions of the plant (number of machines, people etc.). In the case of BIB002 , the whole hybrid model is about the production in the enterprise; SD for the aggregateplanning level and DES for detailed-scheduling level.