Giovanni Romagnoli

Extending value stream mapping: the synchro-MRP case

Nowadays, value stream mapping (VSM) is recognised as the main tool for implementing lean manufacturing. Unfortunately, it always leads to pure pull systems and discourages the adoption of hybrid push/pull ones, although their superiority has been proven in several industrial settings. Due to these issues, this paper presents an enhancement of the standard VSM, which supports the user in designing the future state map of a synchro-MRP system. This new tool includes new mapping icons, simple mathematical formulas and operating guidelines that make it possible to assess the benefits of a synchro-MRP system, with respect to the usual kanban or CONWIP ones. In order to demonstrate the quality and the practical utility of the proposed approach, an industrial application of relevance is finally presented.

A new framework for RFID use cases in fashion and apparel retailing

OBJECTIVE: This paper aims at proposing a new framework for the classification of RFID deployments in fashion and apparel retailing. The framework encompasses several different use cases (UCs) pursued by fashion and apparel retailers in the last decade, and updates, expands and goes beyond what has already been presented in the related literature. DESIGN, METHODOLOGY, APPROACH: We carried out a comprehensive literature review on RFID deployments in fashion and apparel retail. We searched different sources of information, that is, scientific papers, conferences and seminars proceedings, websites, magazines, newspapers etc., up to 160 papers that were carefully analysed and organised in a structured database. This data set also comprehends information from confidential projects. We analyse contents on the level of single RFID projects, that is, feasibility studies, proofs of concept, pilots or deployments. For each project, we determine what specific UCs were at stake. Eventually, the framework of all possible RFID UCs emerged from the analysis, and we set up a panel of industry partners to validate the framework using the Delphi method. FINDINGS: We structured the new framework along two levels: first, 6 categories were identified (i.e., level 1 use cases). Each category was then detailed, resulting in a total of 18 specific UCs (i.e., level 2 use cases). Each level 2 UC corresponds to a very specific objective pursued by an RFID implementation. For each UC, we propose a set of business metrics to evaluate deployment success as well as benefits achieved. PRACTICAL IMPLICATIONS: From a practitioner’s perspective, the framework offers a comprehensive and well-structured overview of the cost- and the revenue-related potentials of RFID implementations in the industry. Researchers, on the other hand, may use the framework to identify opportunities for further research regarding RFID deployments in retailing. ORIGINALITY/VALUE: Our framework is based on the current body of literature, and complements prior studies, which served as the starting point for our research.

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 than BC ones. 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’ 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.

RF-based Locating of Mobile Objects

Misplaced items in retail stores lead to inaccurate inventory assumptions, unsatisfied customers, lost sales and lower revenues of up to 10%. Real-time Locating Systems (RTLS) however, offer a solution to locate items in a defined space such as a retail store. The RTLS market offers a vast number of available solutions and technologies. Analysts forecast a strong growth of the RTLS market. Unfortunately the majority of users -- especially in retail -- are still waiting for cheaper offerings. Locating based on passive RFID is a promising low-cost approach for retail applications. This paper describes the current state-of-the-art in RTLS and shows a use-case of locating garments in retail applications.

Assessing performance of Workload Control in High Variety Low Volumes MTO job shops: A simulative analysis

This paper deals with Workload Control (WLC), one of the best techniques to control Work In Process (WIP) and to stabilize Lead Time (LT) in job-shop systems. Our focus is on the job release strategy and, specifically, on the selection and dimensioning of suitable norms; a challenging problem, which is often the cause of the little industrial use of WLC. Specifically, our aim is to assess whether or not the use of easy to implement norms, appealing also from an operating point of view, may be enough to boost performance of a productive system. To this aim, a thorough discrete events simulation was made, considering a realistic job-shop environment in different operating conditions. Job release was subjected by WLC, regulated by two consolidated norms (i.e., Shop-Load and Bottleneck-Load) and by a novel one, which leverages on the grouping of jobs into families. Obtained outcomes are highly satisfactory, since good performances, in terms of WIP minimization and Due Dates compliance can be obtained, especially in highly constrained productive environments.

Testing and Deploying an RFID-Based Real-Time Locating System at a Fashion Retailer: A Case Study

In this paper, the testing and deployment of an RFID-based Real-Time Locating System (RTLS) at a fashion retailer is presented. An RTLS is a combination of hardware and software systems to determine automatically and in real-time the coordinates of an object. Although this goal might be achieved with different technologies, several studies suggest the centrality of RFID as a locating system technology. Nonetheless, the literature presents a lack of studies that investigate on real applications of RTLS in retailing. To fill this gap, our study reports the testing and deploying phases of an RFID RTLS at the Diffusione Tessile store in Pomezia, Rome (Italy). The selected store is, at present, the biggest of the whole firm in terms of number of garments exposed. During a recent refurbishment of the store, the company installed a RTLS composed of 254 antennas linked through multiplexers to 13 readers. The RTLS was designed after an extensive lab-testing phase, and it is provided with two different algorithms for locating garments on the sales floor area. A first installation of the system was finished in early 2015, but this first implementation resulted in some discrepancies amongst different antennas and some corrections were made. In autumn 2015, the system was then tested for the first time in the field: the results of all the testing phase are reported in the paper. This case study sparks interest and suggests several ideas for a deployment of RTLS in a fashion store. Also, and maybe more important, the points of strength and weakness of our implementation could help practitioners and researchers to maximise the benefits of future RTLS implementations in the fashion industry and discover new prospective research topics within this sector.

RFID technology for blood tracking: An experimental approach for benchmarking different devices

OBJECTIVE: The objective of the paper is to design a testing protocol to measure performances of RFID devices applied to blood supply chain, and to implement an experimental campaign in order to collect performance data. The protocol matches operational conditions in blood supply chain and is particularly tailored to some critical processes, which can benefit from RFID adoption. The paper thus strives at benchmarking performances of inlays, fixed and handheld RFID readers, when deployed in the blood supply chain processes. DESIGN, METHODOLOGY, APPROACH: The adopted testing protocol enables the assessment of performances of RFID devices in processes of the blood supply chain, since it has been developed peculiarly to emulate critical logistics processes. The testing protocol has been designed jointly with hospital personnel involved in every day operations on blood bags and tubes in order to improve processes, in terms of safety and reliability. The testing protocol has been applied to 3 inlays, 2 fixed readers, 1 mobile handheld in 3 logistics processes, all operating according to UHF EPC class 1 gen 2 protocols and ETSI regulations. We measured and compared read rates, accuracies and read times. FINDINGS: The results of the test give a direct insight of performances to be expected from different RFID devices when deployed in a real-world environment. Therefore, it is possible to give answers to how a specific piece of hardware —such as an inlay or a reader —performs, and how it can be effectively used to improve security of patients in healthcare. At the same time, researchers focusing on the business process reengineering of blood supply chain can assess the technical feasibility of the RFID-reengineered logistics processes in order to improve the safety of end users.

Misplaced product detection using sensor data without planograms

Abstract Accurate and timely provisioning of products to the customers is essential in retail environments to avoid missed sales opportunities. One cause for missed sales is that products are misplaced in the store. This can be addressed by fast and accurately detecting those misplacements. A problem of current detection methods for misplaced products is their reliance on up-to-date planogram information, which is often missing in practice. This paper investigates the effectiveness and efficiency of outlier detection methods for finding misplaced products without planograms. To that end, we conduct simulation studies with realistic parameters for different store parameters and sensor infrastructure settings. We also evaluate the detection methods in a real setting with an RFID inventory robot. The findings indicate that our proposed MiProD aggregation of individual detection methods consistently outperforms individual techniques in detecting misplaced products.

Applying lean in the non-Make-To-Stock sector: Criticalities, solutions and applications

Wastes identification and removing has become a key issue to achieve competitiveness and to survive in the modern manufacturing environment. In order to achieve this goal, several manufacturing paradigms have been proposed. Amongst these paradigms, lean production has increased its importance, and it is now recognized as the most influential one. The concept of lean is based on the dichotomy of value and wastes, and its main goal is to meet customers expectations in a better way, by focusing on a continuous waste elimination process. Although Lean originated in Low-Variety-High-Volume manufacturing companies, it has been frequently applied also in other contexts, especially in the non-Make-To-Stock sector, where its application is particularly challenging. Indeed, those manufacturing environments are characterized by a high level of variability, and their performances depend on several interrelated parameters. Within this context, it is widely recognised that no “fool proof” way is available for implementing lean principles, because they must be properly reinterpreted to fit the specific requirements of the industry where they need to be applied. Generally speaking, the non-MTS sector can be broadly parted in two clusters: (i) Make-To-Order companies, where most or all operations to manufacture an end item are only performed after a customer order has been received and (ii) Engineer-To-Order companies, where products are manufactured to meet a specific customers needs and require unique engineering, or at least a significant and specific customisation. Within both these clusters, several lean tools can be applied.

Simulation of two hybrid production planning and control systems: A comparative analysis

The goal of this paper is to analyze and compare the performances of two Hybrid Production Planning and Control (HPPCs) systems, namely CONWIP and Workload Control. Although several implementations of HPPCs reported excellent results, in fact, many authors have discharged the concept, arguing that these systems can only reduce manufacturing lead times and control WIP to the detriment of production rate, punctuality or service level. The paper starts from a brief review of the literature on HPPCs. Afterwards, the paper uses a common simulation model from the literature to compare two simple and easy-to-implement configurations of CONWIP and Workload Control against the baseline of a classic push system. The results of the simulations lead to important conclusions and suggest interesting improvements of simulation models and future directions of research for better understanding HPPCs.