In recent years, the warehouse is no longer viewed merely as a space for storing goods but has become a true profit center. The idea that a warehouse can generate value for the customer is now widely accepted (Richards, 2017; Ghosh & Shah, 2015). Errors in operations, incorrect picking, damaged goods, and delays in order preparation are just a few examples of process non-conformities that originate within the warehouse and can compromise the trust-based relationship with customers (De Koster, Le-Duc & Roodbergen, 2007).

The economic crisis and emerging international dynamics have driven companies to seek greater efficiency and flexibility. Lean and agile philosophies have led organizations to focus on effective inventory management as a way to reduce overall business costs.

The warehouse now faces multiple trends: on one hand, customers demand more frequent and smaller deliveries; on the other, sourcing from the Far East requires holding inventory that cannot be minimized. Furthermore, the shift in the production center of gravity toward Asian countries has transformed many manufacturing sites into distribution hubs. As a result, globalization has led many companies to evolve from production-focused entities into storage and shipping centers. The role of the warehouse has thus become fundamental.

Most definitions describe a warehouse as a facility where goods are received, stored, handled, and organized for subsequent shipment. Once received from a supplier, goods may remain in the warehouse for a certain period until they are needed (Kocifaj, 2019). A warehouse is also a space where various activities take place, depending on its function and its position within a company’s logistics system or supply chain (Marasová & Šaderová, 2018). This implies the execution of one or more processes aimed at ensuring the physical flow of materials and products.

According to Gu et al. (2010), warehouse design problems involve five groups of decisions: defining the overall structure (conceptual design), determining size, calculating layout, selecting storage equipment, and choosing the operational strategy. Furthermore, warehouse planning must also include policies related to order fulfillment/picking, storage, and inventory turnover (Koster et al., 2007; Chan & Chan, 2011).

Warehouse management is an integrated process encompassing several key functions. Among its main objectives is to ensure an efficient and secure flow of goods from receipt to customer delivery. Another essential aspect is inventory management, which involves implementing strategies to maintain optimal stock levels and avoid both shortages and surpluses. Warehouses are increasingly seen as opportunities to improve operational and informational flow optimization, reduce inventory levels, and enable more agile distribution (Vrijhoef & Koselka, 2000).

The primary goals of effective warehouse management include: cost reduction; achieving economies of scale by moving large volumes between logistics centers (Rodríguez et al., 2007); managing variability caused by factors such as product seasonality (Gu et al., 2007); maintaining a high level of customer service (Parikh & Meller, 2008); and integrating flexibility into the supply chain to ensure better responsiveness to market changes (Amiri, 2006).

This study is conducted from a logistics and operations management perspective, with a specific focus on warehouse operations. It does not include inventory management, network design, location planning, or engineering aspects.

Warehouse Operations: Functional Phases and Process Overview

Warehouses can perform a variety of functions depending on product characteristics, customer requirements, and the level of service provided. According to De Koster and Warffemius (2005), the complexity of warehouse operations depends primarily on: (i) the number and variety of items to be handled; (ii) the daily workload; and (iii) the number, nature, and variety of processes required to meet the needs of both customers and suppliers. While operational differences exist—such as between storage warehouses and cross-docking facilities—there is broad consensus in the literature regarding a set of core activities: receiving, storage, order picking, and shipping (van den Berg & Zijm, 1999). This study excludes activities external to the warehouse area, such as transportation processes, inbound procurement, and final delivery.

A comprehensive process framework used to investigate how much attention companies devote to each phase is the one proposed by Tompkins et al. (2010), to which this study adds two additional stages:

Vehicle Access

This phase covers the path taken by transport vehicles from entry gate arrival to parking in the unloading area. Managing this step is essential for both safety and productivity. From a safety perspective, the heavy vehicle's access path must be designed to eliminate or minimize potential interferences—defined in Italian Legislative Decree no. 81/2008 as situations where activities by multiple parties (e.g., contractors and client companies) overlap in space and/or time, creating risk for workers. Poor scheduling of vehicle arrivals can lead to unloading bay congestion, resulting in productivity losses. Similar issues have been documented in maritime container terminals (Torkjazi, Huynh & Shiri, 2018), leading to the development of heuristic approaches (Huynh, Walton & Davis, 2004; Namboothiri & Erera, 2008), mathematical models (Guan & Liu, 2009a, 2009b; Zehendner & Feillet, 2014), truck appointment systems (Schulte et al., 2017), and slot allocation models (Azab, Karam & Eltawil, 2017; Huynh, 2009). Despite advances in technology, warehouse managers and transporters report a continued rise in lost hours due to unanticipated delays, schedule changes, and wait times. To mitigate this, many warehouses—especially distribution centers—implement appointment systems to evenly distribute truck arrivals by limiting the number of vehicles processed within a given time window.

Vehicle Unloading

This phase involves the transfer of goods from transport vehicles into the warehouse. It includes vehicle arrival planning, physical unloading, and goods registration and storage. A key activity here is the assignment of loading bays. Equipment such as pallet jacks, forklifts, or automated systems may be used to move materials. Efficiency in this phase is critical to minimizing cycle times and preventing product damage. De Oliveira et al. (2022) studied the receiving process in a warehouse, implementing improvements such as layout reorganization and workstation balancing, resulting in a 28% cycle time reduction and substantial operational savings.

Receiving
This phase includes all activities associated with the inbound receipt of goods ordered from suppliers. Products are visually inspected to verify packaging integrity and compliance with purchase orders. Accepted goods are then entered into the warehouse management system, updating inventory status (Gu et al., 2007).

Inspection and Quality Control

An extension of the receiving process, this step is necessary when supplier quality is inconsistent or when goods are subject to strict regulatory requirements. Full or sample-based inspections are carried out as needed.

Repackaging
Performed when products arrive in bulk and must be repackaged into single units, sales quantities, or combined into kits or assortments. Repackaging may involve changing packaging (e.g., from cardboard boxes to plastic totes), sorting mixed items into distinct storage locations, labeling incoming goods, or replacing damaged packaging.

Storage (Putaway)

This involves physically placing items into storage locations and includes material handling and positioning. Goods remain stored until requested by internal (e.g., production) or external (e.g., customer) clients. Storage methods vary depending on item size, quantity, and handling characteristics.

Replenishment
This refers to refilling picking locations by retrieving goods from storage areas and relocating them to zones suited for order picking.

Order Picking

Order picking is the core warehouse service provided to customers and garners the most attention, as fast and accurate picking increases customer satisfaction (Baker & Canessa, 2006). Described as the "top-priority activity for productivity improvement" in World-Class Warehousing and Material Handling, it accounts for nearly 50% of operational costs in typical warehouses and is the most labor-intensive process (De Koster et al., 2006). Most warehouse personnel are dedicated to picking, which also occupies over half of total warehouse time (Tompkins & Smith, 1998). In manual-pick systems, travel time is generally a growing function of travel distance (Jarvis & McDowell, 1991; Hall, 1993; Petersen, 1999; Roodbergen & De Koster, 2001b; Petersen & Aase, 2003), making distance minimization a key design and optimization objective.

Sorting
Sorting follows picking and is particularly relevant in high-volume or batch-picking contexts. It involves classifying and separating items or orders based on predefined criteria (e.g., customer, destination, product type, or shipping channel) to streamline packing or shipping. Sorting aims to reduce delivery errors and enhance operational efficiency (De Koster et al., 2007; Boysen et al., 2007).

Consolidation and Packing

This phase follows picking and involves preparing goods for shipment. Items picked at different times, by different operators, or from various zones are consolidated by order. Products or assortments are packaged for safe and practical transportation. This phase also includes generating labels, preparing shipping documents, and weighing orders to calculate shipping costs.

Outbound Quality Check

This final verification ensures that shipped materials and packaging are complete and accurate, and that load unit labels contain the correct information.

Vehicle Loading

This phase mirrors unloading and involves transferring goods from the warehouse to the outbound vehicle.

Vehicle Departure

The same principles described for vehicle access and unloading apply here.

This detailed breakdown of warehouse operations provides a comprehensive framework for analyzing how companies structure, prioritize, and monitor each phase within their logistics systems. Building on this operational model, the following section outlines the research methodology adopted to assess the degree of attention and control applied across these processes in real-world warehouse environments (Gu et al., 2007; Ramaa, Subramanya & Rangaswamy, 2012).

Methodology

The objective of this study is to assess which activities within the warehouse process are considered by companies to be the most strategic for improving operational performance. Companies' level of interest or sensitivity toward specific process phases is monitored through reported past investments or those planned for the near future. This research aims to identify which phases of the warehouse process are most closely monitored by companies, while also drawing attention to those phases that tend to be overlooked. The proposed model offers professionals a checklist of elements to consider when conducting comprehensive performance analysis and improvement initiatives. For academic researchers, it provides a set of specific topics that can be individually explored to propose new solutions and develop improved process designs.

The study was carried out through the following steps:

Phase 1: Literature Review

A review of existing literature was conducted to define the full range of phases that make up a comprehensive warehouse process. The studies analyzed—published between 1996 and 2022—were sourced from the Web of Science and Scopus databases. Search terms were developed inductively, based on preliminary readings of articles focused on warehouse design and management. The final main keywords used were:

• “warehouse management”
• “warehouse storage automation”

Phase 2: Questionnaire Design and Field Interviews

A questionnaire was developed and distributed to supply chain and logistics managers. The initial contact was made via email, followed by direct outreach. Upon agreement, a structured interview was conducted with the manager, accompanied by an on-site visit. The visit followed, step-by-step, the activities outlined in the previously defined warehouse process model.

Phase 3: Assessment of Managerial Sensitivity to Process Phases

Inspired by Carter’s arguments regarding research relevance for managers, the literature review was complemented by interviews with industry professionals to incorporate their insights into the research agenda. Similar methods have been used by Baker and Canessa (2009), Thomas et al. (2011), and Sodhi et al. (2012), who combined literature studies with expert interviews or focus groups to define research opportunities with practical relevance. Many scholars in logistics and warehouse management work closely with practitioners in the field.

One key reason for this close collaboration between academia and industry is to enhance the managerial and practical relevance of academic research. By using both literature review and practitioner insight, future research directions are not solely based on gaps in the literature but also reflect industry needs. This dual approach allows for the proposal of more practically relevant research pathways.

A total of 25 warehouse and supply chain managers were interviewed. The interviews focused on identifying the most actively monitored and managed phases within their warehouse operations (see Appendix A in the ESM). Respondents were selected to represent a diverse range of company types, enabling the identification of common process elements across various warehouse operation contexts. The sample included managers from companies operating in sectors such as food, mechanical engineering, fashion, and furniture. Convenience sampling was used, with all participants working in northern Italy. Convenience sampling is a non-probabilistic technique in which study participants are selected based on practical criteria such as accessibility, geographic proximity, availability at a given time, or willingness to participate (Etikan et al., 2016, p. 2). Most of the participating companies operate at a global level.

The questionnaire sent by email included a series of closed questions answered using a 5-point Likert scale. The follow-up in-person interview consisted of open-ended questions, allowing respondents to freely share their perspectives. Depending on their familiarity and involvement with warehouse management issues, participants were able to explore challenges from different viewpoints. All interviews were recorded, transcribed, and shared with the respondents for approval. The confirmed transcripts were analyzed to identify the key phases of managerial oversight. To identify gaps between theory and practice, the issues reported by respondents were compared with existing literature to determine whether they had already been addressed in scholarly works. Additionally, the frequency with which these issues were mentioned was compared to the prevalence of those topics in the literature, in order to assess alignment.

Research Results

The companies involved in this study are all medium and large enterprises, as defined by the European Commission. According to Recommendation 2003/361/EC, enterprises are classified based on the number of employees and their economic scale, measured through annual turnover or total assets. Specifically, a medium-sized enterprise has fewer than 250 employees and an annual turnover not exceeding €50 million, or a balance sheet total not exceeding €43 million. Large enterprises exceed at least one of these thresholds. This classification is important not only for statistical purposes, but also for determining eligibility for funding programs, incentives, and support policies promoted at the European level. It also helps companies tailor organizational strategies based on their structure and size.

The following table lists the companies that were surveyed between mid-2023 and the end of 2024. All companies are geographically located in Northern Italy, although some operate additional warehouses or facilities in other Italian regions and abroad. The companies span various industrial sectors but are all medium- or large-sized enterprises. In addition to the number of employees (if disclosed) and reported turnover, the table includes two columns highlighting:

• WMS: This column indicates whether the company has implemented a Warehouse Management System to oversee its warehouse operations.
• Warehouse Automation: This field reports whether the company has adopted any form of warehouse automation, ranging from basic solutions such as vertical storage systems to more advanced installations like Automated Storage and Retrieval Systems (AS/RS).

The table clearly shows that WMSs are implemented across both medium and large enterprises, whereas automation solutions are primarily adopted by larger companies. Based on the interviews, the limited adoption of automation is often attributed to difficulties in calculating return on investment, or to operational constraints due to the nature of goods being stored or handled, which often lack standardization. Despite the financial incentives provided by the Industry 4.0 initiative, many firms chose to prioritize investments in production systems over warehouse optimization. On the other hand, some companies in the large-scale retail sector viewed these incentives as an opportunity to pursue automation. A key driver behind automation investments among commercial firms was the need to reduce dependency on human resource variability—both in terms of skill levels and workforce availability.

Table 1: companies involved in the research and their WMS and automation adoption

The questionnaires and subsequent interviews conducted with the companies enabled the creation of the following table, which assesses the actual level of interest or monitoring for each phase of the warehouse process. The data reported reflects the majority of responses received.

• Procedure Standardization: Indicates whether companies have established procedures for that phase, typically communicated through training sessions and the creation of informational documents.
• Performance Indicators: Refers to the presence of metrics specifically used to monitor the corresponding warehouse phase.
• Automation: Reflects the perceived importance of adopting automation solutions in the respective phase.
• Digitalization: Reflects the perceived importance of implementing digital solutions in the respective phase.

The following table provides a synthetic overview of the main warehouse process phases and the degree of managerial attention they receive across the surveyed companies. The evaluation is based on aggregated responses from questionnaires and follow-up interviews, reflecting the most common practices and perceptions. For each phase, the table highlights whether companies have formalized procedures, implemented performance indicators, and recognized the relevance of automation and digitalization. This framework aims to identify which phases are strategically managed and which are still underdeveloped or neglected in operational practice.

Table 2: Warehouse process and level of control of process activity