Integrating value stream mapping and discrete events simulation as decision making tools in operation management

PurposeThe purpose of this paper is to investigate the integration of discrete event simulation (DES) and value stream mapping (VSM) to enhance the productivity of road surfacing operations by achieving high production rates and minimum road closure times. Highway infrastructure is one of the most valuable assets owned by the public sector. The success of national and local economies as well as quality of life of the general public depend on the efficient operations of highways. Ensuring smooth traffic operations requires maintenance and improvements of the highest standard.Design/methodology/approachResearch approach involved the use of primary data collected from direct observation, interviews, review of archival records and productivity databases. Based on this, process maps and value stream maps were developed which were subsequently used to produce discrete event simulation models for the exploration of different optimisation scenarios.FindingsThis research highlights the synergistic relationship between VSM and DES in driving innovation in construction processes. Identified factors that affect roadworks process productivity include machine, manpower, material, information, environment and method-related factors. A DES model is presented to optimise the process and increase the production rates. A hybrid DES-VSM approach ensures an integrated approach to process optimisation.Research limitations/implicationsThis study is an application of hybrid version of previously published DES-VSM framework in the manufacturing sector. The present study has extended and tested its applicability within road surfacing operations. The different what-if scenarios presented in this paper might not be applicable to other parts of the world owing to various constraints. The study has focused on addressing the waste production inherent in pavement laying process. Even though external variables could possibly influence pavement process, those were ignored to allow for in-depth focus on the process under consideration.Practical implicationsRoad users are one of the most important stakeholders that will benefit from the positive implications of this study. Private resurfacing companies and transport departments can optimise their overall process and style of working by comparing their end-to-end process and work plans with the ones mentioned in this paper. It will boost the productivity of equipment like planners, pavers and other machines used for resurfacing operations.Originality/valueExisting approaches to process modelling such as VSM and process diagrams are constrained by their effectiveness in the analysis of dynamic and complex processes. This study presents a DES-based approach to validate targeted improvements of the current state of road surfacing processes and in exploration of different optimisation scenarios.

The main driver of industry 4.0 is data and information for realizing resilient manufacturing systems through data-based decision-making. This requires the data flow from different machinery and its processing. Therefore, a methodical survey on the logical and technical requirements for enabling an efficient data flow can be beneficial since it fastens the process of establishing the data flow and gives production and software engineers a common understanding of the data’s meaning. Hence, data, related metadata like the unit or the frequency of recordings, and technical information, e.g., the machine’s interface or the communication protocol, are necessary. Based on the classical value stream mapping (VSM) as a lean management tool, the first approach for a methodical gathering of data, value stream mapping 4.0, was established in 2016. Since VSM 4.0 provides technical properties for specifying the data flow, some shortcomings were identified, particularly related to technical information. This contribution introduces the VSM 4.0 plus that solved the identified shortcomings by adding new properties. Compared to VSM 4.0, VSM 4.0 plus offers detailed specifications of data points, includes technical information, e.g., used communication protocols, adds information regarding data processing, and enhances the storage and usage dimension by providing more details. Through the added properties, VSM 4.0 plus allows domain and software engineers more efficient collaboration since all required information for establishing the data flow and its processing are united in one methodology. To verify the practicability, the VSM 4.0 plus was applied within several manufacturing-related use cases.

PurposeThe purpose of this paper is to investigate, through a comparative analysis, the applicability of lean manufacturing practices, such as value stream mapping (VSM), for productivity improvement in recycling centres (RCs) aided by multi-criteria decision analysis.Design/methodology/approachThe study is carried out in five RCs that sort the municipal solid waste of Porto Alegre, one of the main cities in Brazil. Since all of the centres present their labour composed by poor communities’ members, cultural and social characteristics may represent an incremental challenge for lean implementation. Further, these centres are organised in cooperatives, in which decisions are taken through a participatory way and all their members are entitled to vote, undermining and retarding the decision-making process.FindingsThe integration of a multi-criteria decision-making tool to the lean practices enables the prioritisation of improvements, complementing the final stage of VSM. In particular, this contribution becomes especially important in cooperatives managed by community, where decisions are often complex and time-consuming. Finally, despite the increasing pressure for better performance of RCs, the existent mindset is still far from the private sector, where lean practices were conceived. Further, the findings suggest that, despite processes similarities, it is not feasible to declare the existence of a one-best practice to such scenario.Originality/valueIn theoretical terms, the authors demonstrate through a multi-case study the adequacy of analytic hierarchy process as a decision analysis tool complementary to the VSM, enabling a broader perspective about this subject. Concerning the practical contribution, the comprehension of the adaptation needs for lean practices implementation within the production context of solid waste RCs provides a framework with guidelines for this sector, when incorporating lean activities. Lean practitioners and eventual municipal authorities involved in improving productivity of community-managed RCs might benefit from this framework, since they will be able to emphasise the development of recommended and already tested lean practices that tend to improve their operational performance.

Fine-Grained Parallel and Distributed Spatial Stochastic Simulation of Biological Reactions

Discrete Event Simulation (DEVS) is a widely used approach for modelling and simulation of dynamic discrete systems. The modern object-oriented DEVS world view regards active objects (entities) passing passive objects (stations) along given path. An event mechanism updates movement of entities, being capable also of collisions and other state-dependent phenomena. Consequently; DEVS can be used for simulation of pedestrian and evacuation dynamics. Classical straightforward modelling approaches, based on abstract classical queuing systems, do not take into account the spatial distributions primarily — only for animation a spatial component is used. But modern object-oriented tools allow modelling of a spatial distribution primarily by means of topological attributes as well in active and passive objects at the modelling level. This contribution discusses the “spatial” features of DEVS simulation systems The chosen simulation tool, Enterprise Dynamics, offers a high flexibility due to its programming language 4d script that allows adding further functionality to the provided elements as well as creating completely new ones.

This article aims to provide a description of fundamental elements of discrete event simulation (DES), the process and the values of applying DES in assisting healthcare design and planning decision-making. More importantly, it explores how new technology such as electronic medical records, real-time location services (RTLS), and other simulation methods such as space syntax analysis (SSA) can facilitate and complement DES. Healthcare administrators increasingly recognize DES as an effective tool for allocating resources and process improvement. However, limited studies have described specifically how DES can facilitate healthcare design. Three case studies were provided to illustrate the value of DES in supporting healthcare design. The first case study used DES to validate a surgical suite design for shorter surgeon walking distance. The second case study used DES to facilitate capacity planning in a clinic through testing the utilization of exam rooms upon various growth scenario. The detailed process data for the current clinic were captured through RTLS tracking. The third case study applied DES in an emergency department for both site selection in master planning and capacity test at various growth scenarios with seasonal volume swing. In addition, SSA was conducted to evaluate the impacts of design on visual surveillance, team communication, and co-awareness. It is recognized that the DES analysis is an effective tool to address the process aspects of healthcare environments and should be combined with post-occupancy evaluation and SSA to address behavioral aspects of operations to provide more solid evidence for future design.

Digital Value Stream Mapping: Application of UWB Real Time Location Systems

This article describes the application of value stream mapping to analyze and redesign the way of managing the materials procurement stage of a project. A framework based on integrated definition (IDEF) methodology, the stream analysis approach, activity-based costing, and discrete event simulation is presented. The stream analysis approach is used to analyze, diagnose, and manage process changes represented using an IDEF model. A dynamic simulation is used to evaluate the impact of the changes considered, to support the analysis of the process, and to model the performance of the proposed process. The overall methodology is demonstrated by applying it to a company whose core business is the design and construction of offshore oil rigs. The company specializes in engineering, procurement, and construction projects and has an annual portfolio of about six projects. Many of these projects have common features in terms of design and components, and they are all also characterized by a short “time to delivery.” For this reason, this study was aimed at assessing the possible effects that the application of new materials management policies could have on reducing both project completion time and the resources required.

Present and future projections of heatwave hazard-risk over India: A regional earth system model assessment

Developing a sustainable manufacturing system is a progressively challenging issue as governments across the world have been enforcing increasingly severe regulations by promoting the reduction of environmental waste for manufacturing and energy-saving production activities. Thus, there is a need for developing a sustainable manufacturing system that can be fully examined by incorporating ecological aspects (e.g., consumed energy) for related operations of a manufacturing system using computer-based discrete event simulation tools. In this study, a combined framework of a novel hybrid fuzzy multi-objective optimization and discrete event simulation approach is presented. We combine ecological and economic data and optimization techniques that are aimed at minimizing economic and ecological objectives in a manufacturing system at an early design phase. Hence, the fuzzy multi-objective optimization model is formulated by incorporating economic and ecological parameters. Again, the discrete event simulation model is established based on a comprehensive performance evaluation of the production system. This study also supports design decisions in determining optimum machine numbers, lighting, and cooling equipment required for the production processes within the sustainable manufacturing in conjunction with the most effective level of material flows. In addition, an integrated Decision-Making Trial and Evaluation Laboratory (DEMATEL)-epsilon constraint approach is applied to handle the multiple-objective optimization problem towards a set of trade-offs among the optimization objectives. A real-life application is carried out for investigating the applicability of the created hybrid framework. The findings of this study demonstrate that this framework is useful as a decision-making tool since it can develop a sustainable manufacturing system design considering an optimal solution associated with amounts of energy usage and CO2 emissions under economic constraints.

Discrete event simulation technologies have been extensively used by industry and academia to deal with various industrial problems. By late 1990s, the discrete event simulation was in doldrums as global manufacturing industries went through radical changes. The simulation software industry also went through consolidation. The changes have created new problems, challenges and opportunities to the discrete event simulation. This paper reviews the discrete event simulation technologies; discusses challenges and opportunities presented by both global manufacturing and the knowledge economy. The authors believe that discrete event simulation remains one of the most effective decision support tools but much need to be done in order to address new challenges. To this end, the paper calls for development of a new generation of discrete event simulation software.

One of the successful strategies in business com- petition is effectiveness of logistic management, especially when agriculture products, which have a short life-cycle, are concerned. This means that time management directly affect freshness of products. This study was based on Lean and RFID technology to reduce the amount of time in non-value-added germinated brown rice (GBR) logistic operations in a rice mill. In this study, it began with analysis of the GBR logistic operations in rice mill after that there was an investigation of 8 operation management. Finally, Value Stream Mapping in current state was drawn to show the GBR logistic operations, while Value Stream Mapping in future state was used to draw current maps integrated with Lean and RFID. The result of design using Lean and RFID showed that the GBR logistic operations significantly reduce time 617 from 3,731.5 minutes accounting for 16.53%. Moreover, according to evaluation analysis, break event point (BEP) is 3 years and the return on investment (ROI) is to be in the following the 28.77%.

Value stream mapping (VSM) is a lean tool which addresses the non-value added activities in time domain. But, it fails to address it in a cost domain. In this work, a new tool called cost value stream map (CVSM) is proposed, which addresses the problems encountered in conventional VSM and cost-time profile (CTP) and maintaining the advantages of both. The determination of work in process inventory and non-value added costs incurred by using CVSM are demonstrated by presenting a case study. An SME in Kerala, India is selected for this. Lean techniques applied on the various non-value added activities in the order of their cost investments 27% reduction in lead time, 27%-32% reduction in WIP inventory and 40%-42% reduction in cost investment while manufacturing the product. The reductions when accounted annually there is a saving of INR.2,17,728 in the value added cost.

Contributors

PurposeSafety and productivity are key concerns in the construction projects. While safety looks to the construction workers need to work in a safe environment, productivity affects the project’s profitability and is of a paramount importance from the project owner’s view. The different perspective to the safety and productivity from these two major players in construction projects poses a potential for the conflict between the two. This problem can be fundamentally addressed by methods concurrently improving project safety and productivity. The paper aims to discuss this issue.Design/methodology/approachTo this aim, a discrete event simulation (DES) based framework applicable was proposed for complex and hazardous operations. The utility of the framework was tested using a case study of an eight-story residential building in the north-east part of Tehran, Iran. The excavation and stabilization operation was identified as the most hazardous and critical operation in this case. The framework could improve safety and productivity of this operation by 38 and 4 percent, respectively.FindingsThis framework is a complement to the conventional construction project safety and productivity planning methods. Its main application is in complex and hazardous construction operations.Originality/valueFor the first time, a comprehensive framework for concurrently improving safety and productivity of an entire project was proposed in this research. DES was used as the main modeling tool in the framework to provide anex-anteevaluation foundation applicable to a wide range of construction projects.