Academic articles

Advancement simulation of tunnel boring machines


In mechanized tunneling a significant loss of performance resulting from weak spots in the supply chain or unforeseen geological conditions is a frequent and costly problem. Furthermore, disturbances of critical machine components can have such impact on the production that unforeseen modifications become necessary. Due to the sequential character the malfunction of one element might evoke cascading-effects which may result in a complete standstill of the tunneling progress. Transparent evaluation of applicable tunnel boring machine designs is essential in order to improve the productivity, avoid unplanned interruptions and to estimate the project duration in general. In order to meet these defiances, this paper presents a multimethod simulation model to investigate the advancement rate of tunnel boring machines. Processrelated disturbances can be considered easily within the presented simulation model. Simulation experiments demonstrate the purposive functionality of the model and visualize the significant influence of technical failure on the overall project performance

Hybrid simulation with loosely coupled system dynamics and agent-based models for prospective health technology assessments


Due to the ageing of the world population, the demand for technology innovations in healthcare is growing rapidly. All stakeholders (e.g., patients, healthcare providers and health industry) can take profit of innovative products, but the development degenerates often into a time consuming and cost-intensive process. Prospective Health Technology Assessment (ProHTA) is a new approach that combines the knowledge of an interdisciplinary team and uses simulation techniques to indicate the effects of new innovations early before the expensive and risky development phase begins. In this paper, we describe an approach with loosely coupled system dynamics and agent-based models within a hybrid simulation environment for ProHTA as well as a use-case scenario with an innovative stroke technology

How to build a combined agent based / system dynamics model in AnyLogic


  AnyLogic allows you to build a simulation model using multiple methods: System Dynamics, Agent Based and Discrete Event (Process‐centric) modeling. Moreover, you can combine different methods in one model: put agents into an environment whose dynamics is defined in SD style, use process diagrams or SD to define internals of agents, etc, etc. Any kind of mixed architecture is possible due to flexible object‐oriented AnyLogic modeling language. The choice of model architecture (how to partition...

Understanding retail productivity by simulating management practices


The retail sector has been identified as one of the biggest contributors to the productivity gap that persists between the UK, Europe and the USA. It is well documented that measures of UK retail productivity rank lower than those of countries with comparably developed economies. Intuitively, it seems likely that management practices are linked to a company’s productivity and performance. Significant research has been done to investigate the productivity gap and identify problems involved in estimating the size of the gap; for example the comparability of productivity indices, historical influences, general measurement issues, and varying sectoral contributions. Best practice guidelines have been developed and published, but there remains considerable inconsistency and uncertainty regarding how these are implemented and manifested at the level of the work place. Indeed, a recent report on UK productivity asserted that, “... the key to productivity remains what happens inside the firm and this is something of a ‘black box’”. Siebers and colleagues conducted a comprehensive literature review of this research area to assess linkages between management practices and firm level productivity. The authors concluded that management practices are multidimensional constructs that generally do not demonstrate a straightforward relationship with productivity variables. Empirical evidence affirms that management practices must be context specific to be effective, and in turn productivity indices must also reflect a particular organization’s activities on a local level to be a valid indicator of performance