Manufacturing System Lean Improvement Design Using Discrete Event Simulation

Lean manufacturing (LM) has been used widely in the past for the continuous improvement of existing production systems. A Lean Assessment Tool (LAT) is used for assessing the overall performance of lean practices within a system, while a Discrete Event Simulation (DES) can be used for the optimization of such systems operations. Lean improvements are typically suggested after a LAT has been deployed, but validation of such improvements is rarely carried out. In the present article a methodology is presented that uses DES to model lean practices within a manufacturing system. Lean improvement scenarios are then be simulated and investigated prior to implementation, thereby enabling a systematic design of lean improvements

Variation Modeling of Lean Manufacturing Performance Using Fuzzy Logic Based Quantitative Lean Index

The lean index is the sum of weighted scores of performance variables that describe the lean manufacturing characteristics of a system. Various quantitative lean index models have been advanced for assessing lean manufacturing performance. These models are represented by deterministic variables and do not consider variation in manufacturing systems. In this article variation is modeled in a quantitative fuzzy logic based lean index and compared with traditional deterministic modeling. By simulating the lean index model for a manufacturing case it is found that the latter tend to under or overestimate performance and the former provides a more robust lean assessment

Improving the efficacy of the lean index through the quantification of qualitative lean metrics

Multiple lean metrics representing performance for various aspects of lean can be consolidated into one holistic measure for lean, called the lean index, of which there are two types. In this article it was established that the qualitative based lean index are subjective while the quantitative types lack scope. Subsequently, an appraisal is done on techniques for quantifying qualitative lean metrics so that the lean index is a hybrid of both, increasing the confidence in the information derived using the lean index. This ensures every detail of lean within a system is quantified, allowing daily tracking of lean. The techniques are demonstrated in a print packaging manufacturing case

A lean assessment tool based on systems dynamics

Lean manufacturing is synonymous with a set of practices used in the identification and elimination of waste related with the manufacturing system, and focusing on what creates value for the customer. Lean assessment tools enable an overall audit of the performance of lean practices, and so are able to identify lean improvements. The interactions between lean practices and their improvements are often latent and need to be investigated: a systems approach can be used to disclose these hidden interactions. In this article, system dynamics is used as a lean assessment tool to assess and improve lean performance for a print packaging manufacturing system

The implementation of 5S lean tool using system dynamics approach

The 5S (sort, set, shine, standardize and sustain) lean tool has been known to improve system performance. In the current study, the short run dynamic implications of the sorting aspect of 5S is investigated using system dynamics. A system dynamics model is developed for a manufacturing case study and simulated to establish the effect of sorting activity on manufacturing throughput. The purpose was to assess, in advance, the system performance outcomes when 5S practices are improved. The simulation results were the stimulus for real life improvements in the system because the simulation results were able to mimic the real-life outcomes. While the simulation results encourage further improvements to be implemented, the model developed in the current paper is replicable in other instances as the variables used in the model are generic and common to most types of manufacturing systems, particularly those new to lean practices. The dynamic analyses of 5S lean practices is not common. The study also reveals some interesting relationships between 5S and other lean practices and between 5S and system performance

The application of a hybrid simulation modelling framework as a decision-making tool for TPM improvement

Purpose The purpose of this paper is to promote a system dynamics-discrete event simulation (SD-DES) hybrid modelling framework, one that is useful for investigating problems comprising multifaceted elements which interact and evolve over time, such as is found in TPM. Design/methodology/approach The hybrid modelling framework commences with system observation using field notes which culminate in model conceptualization to structure the problem. Thereafter, an SD-DEShybrid model is designed for the system, and simulated to proffer improvement programmes. The hybrid model emphasises the interactions between key constructs relating to the system, feedback structures and process flow concepts that are the hallmarks of many problems in production. The modelling framework is applied to the TPM operations of a bottling plant where sub-optimal TPM performance was affecting throughput performance. Findings Simulation results for the case study show that intangible human factors such as worker motivation do not significantly affect TPM performance. What is most critical is ensuring full compliance to routine and scheduled maintenance tasks and coordinating the latter to align with rate of machine defect creation. Research limitations/implications The framework was developed with completeness, generality and reuse in view. It remains to be applied to a wide variety of TPM and non-TPM-related problems. Practical implications The developed hybrid model is scalable and can fit into an existing discrete event simulation model of a production system. The case study findings indicate where TPM managers should focus their efforts. Originality/value The investigation of TPM using SD-DES hybrid modelling is a novelty

Developing Human Right Norms for Investor-State Arbitration: The Needed Panacea for Environmental Injustice?

The dissatisfaction of States and some non-State actors with investor-State arbitration has deepened over the years. This has resulted in agitations for the reform of investor-State dispute settlement. Part of the reform agenda is the need for international investment tribunals to be required to consider human right norms, in appropriate cases, in the determination of arbitration matters before them. This is because, as good as the idea of protecting foreign investments is, if it is not put in its right perspective, it may lead to good government policies and the human rights of indigenes of host communities being sacrificed on the ‘altar’ of investment protection. Thus, this work aims at contributing to the ongoing debate on the need for international investment tribunals to always take public interest into account when deciding disputes before them. In that regard, this work examines the connection between human rights and investor-State arbitration, with particular focus on how these evolving human right norms would produce the needed panacea for environmental injustice. Although the ongoing agitations for reform transcend investor-State arbitration, this work in limited to discussing the specific issue of the need for investor-State arbitration tribunals to be required to give adequate consideration to human right norms in the determination of the matters that come before them. In this work, we used qualitative methodology based on doctrinal approach. The research design used is content analysis, which helps in describing the connection between human rights and investor-State arbitration as well as the concept of developing human right norms in investor-State arbitration. Keywords: Environmental injustice, Human right norms, Investment, Investor-State arbitration, Public interest DOI: 10.7176/JLPG/111-06 Publication date:July 31st 202

Excessive damage awards against host states in international investment arbitration: Achieving the needed equilibrium through justice

The concept of state sovereignty and the unwillingness of governments to submit to judicial authorities outside their states made arbitration a common means of settling investment disputes. International investment arbitration enabled the delocalisation of investment disputes and avoidance of diplomatic protection. However, the issue of high damage awards capable of wiping off a substantial part of a respondent country’s foreign reserve in the guise of investment protection is making states rethink the good in international investment arbitration. If this situation continues unchecked, there are indications that more and more states would revert to diplomatic protection or insistence on local remedies only in resolving international investment disputes, both of which have serious drawbacks. In the light of the above, it is apposite to find a balance between the protection of foreign investments, on the one hand, and the survival of respondent states’ economies, on the other hand. The work adopted the doctrinal approach of qualitative research methodology. This methodology helped with interrogating previous literature that deals with the role equity and justice-rooted principles should play in international arbitration, resulting in the finding that applying such principles would help arbitral tribunals arrive at more appropriate damage awards

Schedule performance measurement based on statistical process control charts

In a job-shop manufacturing environment, achieving a schedule that is on target is difficult due to the dynamism of factors affecting the system, and this makes schedule performance measurement systems hard to design and implement. In the present paper, Statistical Process Control charts are directly applied to a scheduling process for the purpose of objectively measuring schedule performance. SPC charts provide an objective and timely approach to designing, implementing and monitoring schedule performance. However, the use of Statistical Process Control charts requires an appreciation of the conditions for applying raw data to SPC charts. In the present paper, the Shewart’s Individuals control chart are applied to monitor the deviations of actual process times from the scheduled process times for each job on a process machine. The Individuals control charts are highly sensitive to non-normal data, which increases the rate of false alarms, but this can be avoided using data transformation operations such as the Box-Cox transformation. Statistical Process Control charts have not been used to measure schedule performance in a job shop setting, so this paper uniquely contributes to research in this area. In addition, using our proposed methodology enables a scheduler to monitor how an optimal schedule has performed on the shop floor, study the variations between planned and actual outcomes, seek ways of eliminating these variations and check if process improvements have been effective

Damages Awards in International Investment Arbitration and the Question of Fair Compensation

When an arbitral agreement freely entered into between a host nation and a financially stronger multilateral foreign organization breaks down, arbitration is the acceptable mode of settlement of the disagreement. This is in line with the Nigerian Arbitration and Conciliation Act, which makes applicable the convention on the Recognition and Enforcement of Arbitral Awards (New York Convention) on awards made in Nigeria arising out of international commercial arbitration. The objective of this paper is to seek a balance between protecting foreign investments and shielding the economies of host States from destruction through award of excessive damages. The doctrinal approach of qualitative research methodology was adopted, which enabled the interrogation of previous literature that deals with the issue of fair compensation and the role equity should play in international investment arbitration. This library-based research focused on analysing primary data such as cases, statutes and conventions and secondary data in text form. The research methodology adopted helped describe and contributed to the understanding of the concept of damages awards in international investment arbitration and the place of equity in awarding damages. The paper concludes that applying equitable principles will help arbitral tribunals arrive at more appropriate equitable damages based on fair compensation. The implication of the study is that international investment arbitration tribunals may intentionally take into account the actual amount of money invested or expended towards a project in quantifying damages thereby endeavouring not to cross the line of fair compensation. Keywords:Damages awards, Equitable principles, Fair compensation, International investment arbitration, Justice DOI: 10.7176/JLPG/81-02 Publication date: November 30th 202