A lean supply chain (LSC) is a set of organizations directly linked by upstream and downstream value streams between processes that work collaboratively to reduce costs and waste. Currently, supply chains (SCs) have been put to the test as the world has had to face a series of unprecedented disruptions in demand and supply caused by the COVID-19 pandemic. In this paper, a detailed study of constructs and multistructural components was carried out to develop a conceptual reference model that merges Industry 4.0 (I4.0) digital technologies with lean manufacturing tools to reduce waste and minimize costs in the lean supply chain planning (LSCP) context. The main theoretical contribution of this conceptual proposal is to establish a structured relation among the lean, agile, sustainable, resilient and flexible paradigms to improve SC performance by implementing I4.0 enabling technologies. The proposed conceptual model, dubbed as LSCP 4.0, is applied and validated with a case study in a large footwear company. It can help decision-makers and researchers to improve the planning and management of digital SC production processes, even with unexpected disruptions.

Purpose: This research proposes an implementation model of Total Productive Maintenance (TPM) based on the analysis of criticality of machines in the sewing process in the Ecuadorian footwear industry and the identification of unproductive times caused by labor failures.Design/methodology/approach: The project uses field research, presents a quantitative approach, the data collection is done in a horizon of 8 months in which the information is condensed in data tables and takes as a case study one of the most successful companies in the Ecuadorian footwear industry for its initiative to innovate their processes and research new technologies that help increase their efficiency.Findings: The results allow to demonstrate the successful application of the proposed model in the industrial sector of footwear with an increase of average production standards of 5% and a reduction in the number of human errors of 72.2%.Practical implications: The model allows to execute several activities in four phases: preparatory, introduction, implementation and consolidation in order to develop TPM in sewing process.Originality/value: The paper describes a case study in a major shoe company with the aim of reducing the times for unscheduled stoppages and the number of failures.

The present research proposes a implementation model of Lean Manufacturing starting from a production system defined with Theory of Constraints (TOC). The paper describes a case study at a major Ecuadorian footwear company with the aim of reducing delivery times and inventories generated by work in process. Value stream mapping is used to identify wasteful action as opportunities for improvement and with the implementation model both Lean and Theory of Constraints tools are applied. The analysis of activities that add and do not add value in the value stream of the current state and then allows to develop the map of the future state from the relationship between the analysis of constraints and the inventory of the TOC and Pull production and takt time of Lean. The results allow to demonstrate the successful application of the model in the footwear industry with a reduction in nonvalue-added time and inventory of 40% and 78% respectively.

An important aspect in the operation of production systems is to reach the desired amount in the established times and with the minimum volume of inventory in process. To achieve this goal, production control systems are used which are characterized by the effect exerted on the materials flow, whether they are push or pull. In this research a comparative study is made between the production control methodologies of the Pull type system: Kanban, Conwip and DBR, in order to clarify the differences between the different operating mechanisms used by each of them, making use of production parameters such as work in process WIP, cycle time CT and production rate TH to determine the model that presents a better performance. In order to comply with the objective proposed in this project, simulation models were programmed using the Promodel software with the processes of a textile manufacturing industry obtaining as a result that the strategy that presents a better result with respect to the established production parameters is Kanban since an average inventory of 4 lots was obtained, i.e., it presents a reduction of 79.8% compared to the current system. In addition, an average cycle time less than 6.11 hours that represents a 61.1% decrease and a production rate of 0.65 batches/hour.