Anna Azzi

Performance Measurement In Supply Chain: New Network Analysis And Entropic Indexes

Industrial organisations must supply a variety of products and services, meet the needs of fragmented customer expectations, and cope with the consequences of the globalisation of world markets, all of which are producing significant levels of complexity. This study develops a new quantitative measurement of complexity for a supply network based on network analysis, which is often used to study natural ecosystems, focusing in particular on the concept of entropy of information. The research reports advances in both theory on the supply network analysis problem and on its application to industrial contexts. Eight indexes based on entropy are presented. These measures provide a meaningful analysis of the level of complexity in the whole supply network mapping the exchanges of goods between the different actors in the network. The impact of possible modifications of the structure can simply be evaluated using these tools, providing a simple evaluation of the different scenarios. The proposed method takes a holistic point of view to tackle the problem of supply network optimisation. A real world application of the developed new methodology is presented.

Inventory holding costs measurement : a multi-case study

Purpose – Logisticians in the worldwide industry are frequently faced with the problem of measuring the total cost of holding inventories with simple and easy-to-use methodologies. The purpose of this paper is to look at the problem, and in particular illustrate the inventory holding cost rate computation, when different kind of warehousing systems are applied. Design/methodology/approach – A multiple case study analysis is here developed and supported by a methodological framework directly derived from the working group discussions and brainstorming activities. Two different field of application are considered: one related to five companies with manual warehousing systems operating with traditional fork lift trucks; the other is among five companies operating with automated storage/retrieval systems (AS/RS) to store inventories. Findings – The multi-case study helps to understand how the holding cost parameter is currently computed by industrial managers and how much the difference between manual and aut...

Mixed model assembly system with multiple secondary feeder lines: layout design and balancing procedure for ATO environment

The constant research for efficiency and flexibility has forced assembly systems to change from simple/single assembly lines to mixed model assembly lines, while the necessity to reduce inventory has led the transition from single to multi-line systems, where some components are assembled in secondary lines, called feeder lines, connected to the main one by a ‘pull philosophy’. A possible approach to configure such an assembly system is to balance the main line first and use the retrieved cycle time to balance each feeder line separately, which is a questionable solution, especially if operators can perform tasks on both the feeder and the main line. Moreover for its complexity the mixed model balancing problem is usually solved transforming it into a single model by creating a single ‘virtual average model’, representative of the whole production mix. The use of a virtual average model assumes that the processing times of some models are higher or lower than the cycle time, which creates overload/idle time at the stations. This approach, especially in complex multi line production systems, largely reduces the assembly line productivity and increases the buffers dimensions. This paper faces the mixed model assembly line balancing problem in the presence of multiple feeder lines, introducing an innovative integrated main-feeder lines balancing procedure in case of unpaced assembly systems. The proposed approach is compared with the classical one and validated through simulation and industrial applications.

Drug inventory management and distribution: outsourcing logistics to third‐party providers

Purpose – The purpose of the present research is to explore the current situation and future expectations on whether to self‐manage or outsource logistics operations in centralized healthcare networks, and to analyse and quantify the relationships between logistics outsourcing, costs and performance.Design/methodology/approach – The paper is based on a thorough study of a local Italian healthcare network, which evaluated the economic sustainability of logistics outsourcing. The data were collected using interviews, documentation and observations in hospital pharmacies and wards, and by referring to public information available on the internet. A system dynamic simulation followed by a sensitivity analysis was used to investigate the impact of changing key variables as well as the advice of logistics providers.Findings – The sensitivity analysis demonstrates that logistics outsourcing is often the most economical choice.Social implications – Performance‐oriented concepts applied to healthcare have many pro...

Sequencing procedure for balancing the workloads variations in case of mixed model assembly system with multiple secondary feeder lines

In order to increase flexibility and reduce costs, assembly systems are changing from simple mixed-model assembly lines, to multi-lines systems, where some components are assembled in secondary lines, called feeder lines, connected to the main line by a ‘pull philosophy’. The production of different models in such a complex multi-lines assembly system, where the tasks to perform could be very different from model to model, impacts the production with very high workload time variations, with the consequence of lack of productivity. If operators can perform tasks on different stations on both the feeder and the main lines these time variations can generally be absorbed. But if working across the stations is not possible (closed stations), the balancing of these workload time variations becomes critical. In such contexts the consolidated approach, that allows to configure mixed-model-multi lines assembly system with a single average model representative of the whole mix, can be very limited and is unable to bring substantial results. This paper aims to introduce an innovative sequencing model for mixed-model-multi-lines system, in the case of closed stations, in which it is possible to obtain, after a first long term configuration, a short term balancing, using an appropriate sequencing, for a given production mix and characteristics of the assembly system. The proposed procedure is applied to un-paced assembly lines and validated through simulation and industrial applications.

Variability‐oriented assembly system design: a case study in the construction industry

Purpose – The purpose of this paper is to apply group assembly (GA) considerations to the construction industry and to provide evidence of construction sector industrialization with quantitative results. Moreover, a flexible assembly system is proposed, especially designed to cope with variability: this can be easily extendable to other industrial sectors, especially when dealing with extremely variable environments.Design/methodology/approach – The paper presents a case study conducted at an Italian company leader in the design, manufacture and installation of architectural claddings and lightweight continuous facades.Findings – The research empirically demonstrates how the application of GA and the creation of project families lead to consistent enhancement also within the construction industry. The case study reveals great improvement in terms of both operating and ergonomic performances, agile assembly system reconfiguration design and make span reduction. The possibility of correlating a new project ...