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Publications

Publications by SEM

2022

Criteria to consider in a decision model for collaborative robot (cobot) adoption: A literature review

Authors
Silva, A; Simoes, AC; Blanc, R;

Publication
2022 IEEE 20TH INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS (INDIN)

Abstract
Collaborative robots are being increasingly used by manufacturing companies due to their potential to help companies cope with market volatility. Before introducing this technology, companies face the decision phase where they determine the investment feasibility. Decision models for cobot adoption can assist decision-makers in this task, but they require previous identification of decision criteria. Since existing literature overlooked this issue, this study aims to provide a list of decision criteria that can be considered in the cobot adoption decision process. These criteria were identified by a literature review of the benefits, advantages, and disadvantages of cobot adoption. Results show that flexibility, competitiveness, ergonomics, quality, safety, space, mobility, ease of programming, technical features, human-robot collaboration, and productivity are important aspects to consider when deciding whether to invest in cobots. The findings of this study provide a better understanding of the decision process for cobot adoption by listing decision criteria along with some indicators, which is an important input for the design of a decision-making process.

2022

On the impact of adjusting the minimum life on receipt (MLOR) criterion in food supply chains

Authors
Santos, MJ; Martins, S; Amorim, P; Almada Lobo, B;

Publication
OMEGA-INTERNATIONAL JOURNAL OF MANAGEMENT SCIENCE

Abstract
The Minimum Life on Receipt (MLOR) is a widely used rule that imposes the minimum remaining age a food product must be delivered by the producer to the retailer. In practice, this rule is set by retailers and it is fixed, around 2/3 of the age of products regardless their shelf life. In this work, we study single and two echelon make-to-stock production-inventory problems for fixed-lifetime perishables. Mixed-integer linear optimization models are developed considering the MLOR rule both as decision variable and fixed parameter. When the MLOR rule is a variable, it is considered either a sole decision of the producer or a collaborative decision between retailer and producer. The goal of this work is to compare the supply chain performance considering this innovative setting of optimal MLOR (as a variable) against the traditional setting of fixed MLOR rule. The computational results suggest that allowing flexible MLOR rules according to the shelf life of products and the operational requirements of the producer benefit both entities in the supply chain. In particular, reducing the MLOR requirement in up to 12% does not interfere substantially with the average freshness of products arriving to the retailer, but reduces extensively surplus/waste generation at the producer while keeping a small amount of waste at the retailer.

2022

A comprehensive framework and literature review of supplier selection under different purchasing strategies

Authors
Saputro, TE; Figueira, G; Almada Lobo, B;

Publication
COMPUTERS & INDUSTRIAL ENGINEERING

Abstract
Supplier selection has received substantial consideration in the literature since it is considered one of the key levers contributing to a firm's success. Selecting the right suppliers for different product items requires an appropriate problem framing and a suitable approach. Despite the vast literature on this topic, there is not a comprehensive framework underlying the supplier selection process that addresses those concerns. This paper formalizes a framework that provides guidance on how supplier selection should be formulated and approached for different types of items segmented in Kraljic's portfolio matrix and production policies. The framework derives from a thorough literature review, which explores the main dimensions in supplier selection, including sourcing strategy, decision scope and environment, selection criteria, and solution approaches. 326 papers, published from 2000 to 2021, were reviewed for said purpose. The results indicate that supplier selection regarding items with a high purchasing importance should lead to holistic selection criteria. In addition, items comprising a high complexity of supply and production activities should require integrated selection and different sources of uncertainty associated with decision scope and environment, respectively, to solve it, as well as hybrid approaches. There are still many research opportunities in the supplier selection area, particularly in the integrated selection problems and hybrid solution methods, as well as in the risk mitigation, sustainability goals, and new technology adoption.

2022

E-GovSTP: An E-Government Model for a Small Island State, the Case of Sao Tome and Principe

Authors
Vaz, DN; Sousa, B; Mamede, H;

Publication
INFORMATION SYSTEMS (EMCIS 2021)

Abstract
Literature posits that most data and research on E-Government dominantly focuses on large economies where social, political, organizational and economic aspects of these local contexts significantly differ from other parts of the world. One such part is the group of island states specifically referred to as Small Islands Developing States (SIDS), sharing common challenges of reduced size, diseconomies of scale, impact of climate changes and other challenges. E-Government models should be adapted to local context, and for SIDS this entails understanding the local context so as to formulate a sustainable model. Even though we find studies and models for SIDS, significant differences exists among SIDS that warrant individual approaches. An example of a SIDS is Sao Tome and Principe, where the government is involved in E-Government initiatives. This is visible at the Ministry of Finance where different interacting Departments have developed systems and software tools to manage business processes. These systems and tools are used for interactions internally and with public and private sectors. However, for implementation, there is a lack of a centralized, interoperable vision or directive. Consequences are high total cost of ownership, subsequent costs with interoperability and maintenance, and, in the end, deficient long-term sustainability. Considering the impact of costs of information technology initiatives to the public budget, financed in its majority by development and bilateral assistance, there is a need for an E-Government model that prescribes directives for a sound, interoperable and sustainable E-Government implementation. We propose the development of E-GovSTP, a framework/model that intends to combine technical considerations and aspects of the local context to formulate guidelines for E-Government implementations in the Ministry of Finance. This artifact shall be developed through sound theoretical foundation, application of established standards and guidelines to areas of privacy and security, interoperability and system and communications. Additionally, the fundamental aspects of the local context (political, social and organizational) shall be factored into the model in order to guarantee the sustainability having in mind existing technical, material and financial constrains the country faces.

2022

Real-Time Detection of Vehicle-Based Logistics Operations

Authors
Ribeiro, J; Tavares, J; Fontes, T;

Publication
INTELLIGENT TRANSPORT SYSTEMS (INTSYS 2021)

Abstract
Geolocation data is fundamental to businesses relying on vehicles such as logistics and transportation. With the advance of the technology, collecting geolocation data become increasingly accessible and affordable, which raised new opportunities for business intelligence. This paper addresses the application of geolocation data for monitoring logistics processes, namely for detecting vehicle-based operations in real time. A stream of geolocation entries is used for inferring stationary events. Data from an international logistics company is used as a case study, in which operations of loading/unloading of goods are not only identified but also quantified. The results of the case study demonstrate the effectiveness of the solution, showing that logistics operations can be inferred from geolocation data. Further meaningful information may be extracted from these inferred operations using process mining techniques.

2022

A Tool for Air Cargo Planning and Distribution

Authors
Costa, D; Santos, AS; Bastos, JA; Madureira, AM; Brito, MF;

Publication
INNOVATIONS IN BIO-INSPIRED COMPUTING AND APPLICATIONS, IBICA 2021

Abstract
In this paper, a decision support application, for the air cargo planning and distribution, is proposed. The freight forwarding sector has been working to be assertive and efficient in responding to the market through an efficient approach to planning and allocation problems. The main goal is to minimize costs and improve performance. A real air cargo distribution problem for a freight forwarder was addressed. This project emerged from the need to efficiently plan and minimize costs for the distribution of thousands of m(3) (cubic meters) of air cargo, while considering the market restrictions, such as aircraft availability and transportation fees. Through the GRG algorithm adaptation to the real problem, it was possible to respond to the main goal of this paper. The development of an easy-to-use application ensures a quick response in the air distribution planning, focusing on cost reduction in transportation. With the application development it is possible to obtain real earnings with immediate effect.

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