Project scheduling with multi skilled resources: a conceptual framework

Projects’ success depends, mostly, on people’s motivation and competences. A good plan is essential, but it is insufficient if the project manager is incapable to dynamically reassign people to project’s tasks, so as to create multi-skilled teams and to avoid multi-tasking and over-allocation. In this regard, several models dealing with the “Multi Skilled Work Force Scheduling Problem” have been proposed, but unfortunately, most of the works produced so far has not yet found its way into practice. This is mainly because project scheduling and resources allocation are jointly considered, a fact that leads to complex and rigid mathematical formulations and that poses serious constraints on the precision of the input data. Since projects are, by their very nature, uncertain entities, we believe that it is preferable to abandon the over optimistic idea of a global optimum, in favour of a suboptimal but stable and feasible solution. To this aim the paper proposes a heuristic framework that extends the well-known “Dynamic Scheduling” approach. Specifically, the problem is tackled in a hierarchical way: project scheduling is solved first and resource allocation is solved next, considering tasks durations as fixed constraints. In doing so, our focus is on the resources allocation phase, and the objective is to assure an almost perfect matching between resources’ skills and tasks requirements, so as to assure project quality and, also, a harmonious development of the workforce. Possible approaches, based on mathematical programming, which could be easily implemented in project management software, are presented and discussed

Using SCRUMBAN methodology for production planning and control in luxury/fashion manufacturing companies

Operations planning and control has long been dealt with in many ways, mostly with mathematical and analytical approaches. These approaches work properly at a high level, but they have not proved suitable at the shop floor level, where, in order to cope with frequently emerging problems, what managers need is detailed information concerning the level of Work In Process (WIP) and the actual load of both equipment and resources. This issue is particularly evident in the luxury/fashion market, where, due to the continuous and rapid changes in fashions’ trends and to the need to interface with dozen of suppliers, reactivity is vital and managers are urged for planning and analysis tools that are extremely simple and easy to use. In this regard, SCRUMBAN, a recently introduced Visual Management technique, which integrates SCRUM (a widely adopted project planning technique in the software field) with Kanban, is emerging as a powerful way to control WIP, visualize loads, synchronise internal and external flows and, lastly, to motivate people. In response to a gap in the technical literature the paper focuses on this topic with the following objectives: (i) analyse the main characteristics of the SCRUMBAN technique, (ii) propose an original methodology and a structured framework for the development of this technique in the manufacturing field and (iii) provide a guideline for the application of the instrument in the luxury/fashion sector. The last point is addressed through a real case-study, developed in an Italian fashion firm, which gave outstanding preliminary results

Beilinson-Flach elements and Euler systems I: syntomic regulators and p-adic Rankin L-series

This article is the first in a series devoted to the Euler system arising from p-adic families of Beilinson-Flach elements in the first K-group of the product of two modular curves. It relates the image of these elements under the p-adic syntomic regulator (as described by Besser (2012)) to the special values at the near-central point of Hida's p-adic Rankin L-function attached to two Hida families of cusp forms.Peer ReviewedPostprint (author’s final draft

A Biased-Randomized Discrete Event Algorithm to Improve the Productivity of Automated Storage and Retrieval Systems in the Steel Industry

[EN] In automated storage and retrieval systems (AS/RSs), the utilization of intelligent algorithms can reduce the makespan required to complete a series of input/output operations. This paper introduces a simulation optimization algorithm designed to minimize the makespan in a realistic AS/RS commonly found in the steel sector. This system includes weight and quality constraints for the selected items. Our hybrid approach combines discrete event simulation with biased-randomized heuristics. This combination enables us to efficiently address the complex time dependencies inherent in such dynamic scenarios. Simultaneously, it allows for intelligent decision making, resulting in feasible and high-quality solutions within seconds. A series of computational experiments illustrates the potential of our approach, which surpasses an alternative method based on traditional simulated annealing.This work was partially funded by the Horizon Europe program (HORIZON-CL4-2022-HUMAN-01-14-101092612 SUN and HORIZON-CL4-2021-TWIN-TRANSITION-01-07-101057294 AIDEAS), as well as by the Generalitat Valenciana (PROMETEO/2021/065)Neroni, M.; Bertolini, M.; Juan, AA. (2024). A Biased-Randomized Discrete Event Algorithm to Improve the Productivity of Automated Storage and Retrieval Systems in the Steel Industry. Algorithms. 17(1). https://doi.org/10.3390/a1701004617

The impact of RFID technologies on inventory accuracy in the apparel retailing: Evidence from the field

In this paper, we assess the level of inventory accuracy that can be reached by adopting radio frequency identification (RFID) technology for inventory count operations in the fashion retailing. Thanks to an in-field implementation, we carried out two series of RFID inventory counts and compared the resulting accuracy level with that obtained exploiting the traditional barcode (BC) technology, so as to highlight the main pros and cons of the RFID adoption. As a general conclusion, the findings from the experimental campaigns and the analyses carried out suggest that RFID inventory counts are more reliable thanBCones. Moreover, under several circumstances, RFID allows detecting out-of-stock situations that are not evident when using either the BC technology or the inventory data stored in the company\u2019 information system. From those findings, a trend of the inventory accuracy as a function of the time required for RFID inventory counts is empirically derived. Such a trend can be exploited in practical cases to estimate the accuracy level achievable with inventory counts depending on the time dedicated to those activities

Maturity Models in Industrial Internet: a Review

The introduction of assembly lines in industrial plants marked the beginning of the third industrial revolution. The support of information technology has enabled continuous progresses, up to the digitalisation of the processes. In this context, the further innovation characterised by the introduction of Cyber-Physical Systems and other enabling technologies has allowed the fourth industrial revolution. Proposed by the German government, Industry 4.0 appealed to both researchers and practitioners. Since the appearance of the term Industry 4.0, the linked-term Industrial Internet has been introduced to indicate the technology stack and knowledge management required by Industry 4.0. Industrial Internet makes a factory smart by applying advanced information and communication systems and future-oriented technologies, as well as new principles of knowledge management. Undeniably, such a system introduces greater complexity in terms of technologies, knowledge and socio-cultural aspects. Companies are often unprepared to deal with innovation issues, because they lack knowledge and competences and they are not culturally prepared for the relative novelties, but especially because they lack the necessary technological pre-requisites to develop the appropriate technology stack. From this perspective, different models of maturity have been developed, both in academic and technical environments, to support companies in understanding their position within the paradigm of the Industrial Internet. Starting from a quantitative review of the maturity models designed in the general literature, this article develops a qualitative review of the models applied in Industry 4.0, characterising all relevant models and proposing future perspectives to improve existing models and develop new ones

Optimizing Retrieving Performance of an Automated Warehouse for Unconventional Stock Keeping Units

In recent years, the diffusion of automated warehouses in different industrial sectors has fostered the design of more complex automated storages and handling solutions. These circumstances, from a technological point of view, have led to the development of automated warehouses that are very different from the classic pallet Automated Storage and Retrieval Systems (AS/RS), both in terms of design and operating logic. A context in which these solutions have spread is the steel sector. Warehouses with innovative layouts and operating logics have been designed to move metal bundles of different sizes, weights and quality levels, instead of standard, interchangeable stock keeping units. Moreover, picking is often not allowed in these warehouses, due to the configuration of the loading units. In this work we propose a meta-heuristic algorithm based on the Simulated Annealing (SA) procedure, which aims to optimize performance during the retrieving phase of an automated warehouse for metal bundles. The algorithm translates the customers’ requests, expressed in terms of item code, quality and weight into a list of jobs. The goal is to optimize the retrieving performance, measured in missions per hour, minimizing the deviations in quality and weight between customer request and the material retrieved. For the validation, a simulation model of an existing warehouse has been created and the performance of the algorithm tested on the simulation model has been compared with the current performance of the warehouse

Bayes pulmonary embolism assisted-diagnosis: a new expert system for clinical use

Background: The diagnosis of pulmonary embolism demands flexible decision models, both for the presence of clinical confounders and for the variability of local diagnostic resources. As Bayesian networks fully meet this requirement, Bayes Pulmonary embolism Assisted Diagnosis (BayPAD), a probabilistic expert systems focused on pulmonary embolism, was developed. Methods: To quantitatively validate and improve BayPAD, the system was applied to 750 patients from a prospective study done in an Italian tertiary hospital where the true pulmonary embolism status was confirmed using pulmonary angiography or ruled out with a lung scan. The proportion of correct diagnoses made by BayPAD (accuracy) and the correctness of the pulmonary embolism probabilities predicted by the model (calibration) were calculated. The calibration was evaluated according to the Cox regression-calibration model. Results: Before refining the model, accuracy was 88.6%. Once refined, accuracy was 97.2% and 98%, respectively, in the training and validation samples. According to Cox analysis, calibration was satisfactory, despite a tendency to exaggerate the effect of the findings on the probability of pulmonary embolism. The lack of some investigations (like Spiral computed tomographic scan and Lower limbs doppler ultrasounds) in the pool of available data often prevents BayPAD from reaching the diagnosis without invasive procedures. Conclusions: BayPAD offers clinicians a flexible and accurate strategy to diagnose pulmonary embolism. Simple to use, the system performs case-based reasoning to optimise the use of resources available within a particular hospital. Bayesian networks are expected to have a prominent role in the clinical management of complex diagnostic problems in the near future