1. Introduction

In various respects, as stated in the literature, the word “inventory” has been defined. There have been three definitions that appear to be more adaptable to the subject of this thesis. Inventories include raw materials, suppliers, parts, processes, and completed products, which are available at many locations within a company’s production and logistical channels (Ballou 2004). The inventory of every object or resource utilized in an organization is according to Chase and others (2004). An inventory system is a collection of policies and procedures that monitor inventory levels and determine what stock levels need to be re-stocked and how large orders should be maintained. Finally, inventory or stock is defined by Pycraft et al. (2000) as “the storage accumulation of resources within the processing system. In order to keep inventories, a tax office holds clients who are processed and usually refers to their inventory of them as a queue.

Inventory management has frequently meant excessive inventory and excessive management, administration, and inventory. Excesses in either direction may be subject to harsh fines. As technical development has improved the company’s capacity to create items in substantial numbers more quickly and with several design variants, inventory concerns are proliferating. The public has exacerbated the situation by being receptive to modifications and frequent design revisions (Tersine, 1982).

The strategic advantages of inventory management and production planning and planning have been evident since the mid-1980s. The business press has underlined Japanese, European, and North American companies’ success in reaching incomprehensible production and distribution efficiency and efficiency. Several corporations have once again ‘raised the bar,’ integrating their supply chains with other companies in recent years. They exchange, for example, information such that the fluctuation of the demand is considerably smaller instead of answering unknown and fluctuating demands (Silver, Pyke, and Peterson, 1998: 9).

Silver and others (1998) argue that productivity improvements have been sought by lowering direct labor expenditure per unit of production in the U.S. and other western countries. The high work content of many produced items was a reasonable approach. In the last few years, however, the share of unit costs from work decreased steadily. For U.S. companies in 1985, the ratio of acquired material to sales was 60.0% (in USD). Even big manufacturing companies, such as U.S. automobile assemblers, buy up to 60% of the product’s value. This means that inventory management is an area that is very promising to enhance productivity. Due to their outstanding quality and managerial performance, Japanese businesses earned much-deserved recognition in the mid-to-late 1980s. The massive interest in manufacturing just-in-time (JIT) shows that managing inventories work-in-process is also an area that may be improved.

A company is to satisfy its client demands to achieve its organizational objectives. The desire of customers in a firm to keep sales and expand them was always a significant concern. Harrison (2001) says that ‘the consumer has to be directly connected to the customer first, and that these information channels have to speak the language of the customer second. Learning what thrills or annoys a client through surveys and interviews can be conducted individually or in groups. Customer preferences, buying patterns, attitudes to certain goods, and satisfaction with service may be gathered in order to build distinct customer profiles not based on assumptions and impressions.”

Monczka and others (2002) added that customer experience comprises a wide range of actions to ensure that customers are happy beyond their initial selling with a product or service. This implies that a company has specialized account managers that oversee the promotion, inventory monitoring, and customers’ delivery schedules. Customer training or support workers may need to reply 24 hours a day to your telephone query. A network of spare part distribution facilities that quickly replace components and parts may be included in customer services.

2. Methodology

The study was conducted using secondary information. Journal articles, internet sources, and online books were used. The search was done using text words like “inventory,” “inventory management,” “supply chain,” and “trends.” The information was synthesized to form the term paper.

3. Inventory management

3.1 The justification for inventory

There are several reasons why firms have stock. Four motivations for owning stock, namely: Bloomberg, Lemay, and Hanna (2002), identified:

3.1.1 Scale savings

An enterprise can achieve economies of scale in production, purchase, and shipping by keeping an inventory. When the company buys significant volumes, quantity discounts are granted. Transport, in turn, can move more significant quantities and achieve economies of scale via better use of equipment.

3.1.2 Offer and demand equilibrium

Some firms must stock up to benefit from occasional demand. Where demand is relatively consistent but seasonal input materials such as cans are available, a completed stock will respond to demand when the material is out of stock.

3.1.3 Specialisation

Inventory permits specialized companies with subsidiaries. The final items can be shipped straight to the clients or to a warehouse rather than producing numerous products. Each factory can achieve economies of scale through extended manufacturing processes by specializing.

3.1.4 Protection against uncertainty

An essential motive for inventing, i.e., for compensating demand uncertainties. If demand rises and the stockpiles of raw materials go down, the manufacturing line stops until new materials are provided. Also, a lack of process work means that the product cannot be completed. Finally, if client orders go beyond the availability of finished items, the ensuing inventories could result in lost consumers.

3.2 Types of inventories

Inventories may be classified into six different types, according to Stock and Lambert (2001), that is to say:

3.2.1 Cycle stock

The cycle stock is a replenishment stock that is necessary to satisfy demand safely when demand and refill periods (lead times) can be predicted nearly accurately by the business. While the complexity of inventory management is eliminated by continual demand and lead times, may I take this example to explain the basic concepts of inventory.

3.2.2 In-transit inventories

In-transit stocks are things that are stored on the road everywhere. They can be regarded as part of a cycle stock but they are not available until it is sold or exported to the destination. The in-transit inventory should be treated as an inventory, as the purchase, sale or subsequent repatriation items are not accessible in order to compute the expenses for carriage in inventory.

3.2.3 Safety or buffer stock

Due to uncertainty in demand and lead times, safety or buffer stock is better kept than cycle inventory. The aim is to assign a share of the average inventory to meet demand in the near term and lead times. The average inventory at a facility that requires or contributes to a time variability equates to half the order plus the security inventory.

3.2.4 Speculation stock

For purposes other than meeting present requirements, the inventory of speculation stocks is kept. In order to get bulk discounts, for example, material may be bought in amounts more extensive than necessary because of the projected price increases or material shortages or to prevent a possible strike.

3.2.5 Inventory seasonal

Seasonal stock is a kind of speculation stock, including stock build-up before the season begins to keep the workforce steady and stable output or, for agricultural products, stock built up due to a growing season limiting accessibility throughout the year.

3.3 Inventory cost

Gourdin (2001) states that three sorts of expenses must be taken into account in determining the inventory levels.

3.3.1 Holding/carrying cost

Costs for ownership include warehousing, handling, insurance, taxes, obsolescence, robbery, and products finance interest. These costs grow with the increase in inventory levels. Management frequently purchases modest amounts in order to avoid carrying expenses. Instead, then trying to determine the monetary worth of each expense separately, holding costs are usually measured as a percentage of unit value (e.g., 15%, 20%). This technique reflects the difficulties of determining, for example, obsolescence or theft, a definite per unit cost.

3.3.2 Ordering cost

Ordering costs include the costs linked to the placement of an order, including staff costs in the procurement department, communications, and the processing of the accompanying documents. Such expenses would be reduced by placing high volumes of orders in a limited number. Costs are usually stated by monetary value per order, as opposed to carrying expenses.

3.3.3 Stock-out cost

Costs for stock-out include loss of short- and long-term sales. These are perhaps the most complex charges to calculate, but certainly, the most significant ones since they reflect the expenditures borne by clients (internal or external). If these expenses are not understood, management may keep inventory levels higher (or lower) than customer requirements may warrant.

3.4 Inventory classification models

Models for the categorization of inventories assist in assigning time and money to inventory management, and classification systems allow firms to work with many product ranges and inventory units. Thus two models relating to the classification of inventories have been identified by Bloomberg and others (2002). These models are explored to offer background information on the categorization of inventories.

3.4.1 ABC analysis

The study of ABC categorizes items depending on significance, according to Bloomberg and others (2002). Cash flows, lead time, inventory outs, inventory expenses, the volume of sales, or profitability are essential. After the ranking factor is selected, breakpoints for classes A, B, C are selected. The highest 20% may be A articles, 30% B articles, and the remaining C. Each category might be distributed (Ballou 2004).

3.4.2 Critical value analysis

More emphasis is paid to C items in the critical value analysis (CVA). CVA analyzes items based on inventory rates, but they classify things comparable to ABC. In general, it covers three to five categories: top, high, medium, low, and very low priority.

3.5 Symptoms of poor inventory management

Some indications enable improper inventory management to be discovered. In order to detect inadequate inventory management, Lambert and stock of (2001) consider the following elements: An rising number of returns; dollar increases in stock investments with back-orders remained steady; high customer turnover rates; an increasing number of canceled orders; occasional shortage of storage capacity and wide variance in inventory turnover across retail stores.

3.6 Inventory control systems

Control of inventories is the activity to organize consumers’ access to goods. It organizes the acquisition, production, and distribution functions by marketing requirements. This function involves delivering current sales products, new products, consumer products, replacement parts, outdated articles, and other suppliers (Wild 2002).

Wild (2002) adds that it aims at optimizing the following three objectives: customer services, stock costs, and operating expenses as part of inventory control in company operations.

According to Hugo and Rooyen (2002) inventory control guarantees an adequate inventory that meets quantity, quality, time, and place needs and regulates pricing. (2002). Four types of stock monitoring systems are mentioned: fixed order volume system, a system of cycle ordering, a JIT method, and a system of material requirements planning (MRP).

3.7 Improvement of inventory management

In order to enhance inventory management, six actions were emphasized by Gourdin (2001). These efforts will tell companies about improved inventory management. These measures are discussed.

3.7.1 Engagement for top management

Since smaller inventories affect many various components of logistics systems, senior management must guarantee that all these operations work together to satisfy customer demands without excessive inventory luxuries.

3.7.2 ABC analysis of all inventory items

The administration must first realize that inventory products are the major contributors to the objectives of the company. For example, those few products that produce maximum revenues or are seen by the significant clients of the company as critical tasks would be classified “A” items, which might be kept at almost 100% availability. The bulk of the products in the inventory is referred to as “B” items that may be sustained at levels of 80%, for example. Finally, certain low-demand products designated as “C” can still be stored or stored in inadequate amounts.

3.7.3 Performance improvement in other logistical activities

Managers should oversee the efficiency of the remainder of the logistics chain. Inventory policies may have evolved to hide other issues that should be addressed immediately. For example, the management can determine that, via the analysis of transport, order processing, and warehousing operations, order cycle variability can be minimized by enhancing activities that reduce inventory demand.

3.7.4 Forecast for improved demand

Demand estimates are also a technique to decrease predicted fluctuation in comparison to actual sales. Better approaches to forecasting may be used to forecast actual sales correctly.

3.7.5 Inventory management software

Software for practically every inventory management status is presently available, and managers may track sales by item, expenses, inventory time, and other variables. Many of the comprehensive packages are designed according to the type of inventory concerned, depending on various planning material needs (MRP) or distribution requirements (DRP). Briefly, MRP handles manufacturing materials and inventories, whereas DRP maintains the final product inventory. DRP and MRP ensure accurate control over material flow from the supplier to the customer through the logistics system.

3.7.6 Postponement involves modifying or customizing products after the primary manufacturing process is complete

The final product configuration might be postponed or even completed after delivery until the distribution cycle. Braglia and others (2004) have shown that any improvement in the management of this type of inventory is practically desirable and valuable in terms of improved factory performance and reduced investment in stocks, based on their research into a method multistakeholder classification for the management of repayment stocks.

3.8 Inventory management policies

Three policies were established under healthy inventory management by Bowersox, Closs, and Cooper (2002).

3.8.1 Periodic review, order-up-to policy (T, S)

(T, S) the order-up-to-level where T is the set time between orders and S. When to order: orders are placed as clockwork every T days. To companies who cannot check their stock levels in real-time or want to place orders to the providers at periodic intervals, the application of a fixed reorder interval is beneficial. How much to order: the inventory level is assessed, and the difference between that level and the order-up level S is calculated. When the level of the inventory is seven and S = 10, three units should be ordered. Comment: This is the most detailed strategy to apply and the least agile to meet demand and temporal variations.

3.8.2 Continuous review, fixed order quantity policy (Reorder Point, Order Quantity) (R, Q)

(R, Q), where R is the place of reordering and Q is the quantity of order. Where to order and how to comment.

3.8.3 Continuous review, order-up-to policy (Min/Max) (s, S)

(s, S) termed the “littles, large S,” with s being the point of reordering and S being the amount of reordering. More widely known is this policy (Min, Max).

When to buy: Orders shall be placed as soon as the stock dips to or below the Min.

What to order: The order size is different. When the Min is achieved or broken, that is the space between the Max and the existing inventory. Comment: (Min, Max) reacting even more than (R, Q) because the orders are adjusted to consider the amount of inventory below the Min. The ‘ base stock policy ‘ is the standard version when the request is either zero or a unit, Min = Max – 1.

4. The relationship between inventory management and supply chain management

The supply chain is a procedure that should be known to all of us as it plays a vital part in an organization’s success. On the other hand, since the company is one of its drivers, inventory, which affects the success of this company, plays a significant part in the supply chain. In order to develop a plan that will undoubtedly contribute to the company’s success, it is necessary to grasp how inventory management is connected or tied to a supply chain (All Answers Ltd, 2018).

Firstly, the inventory comprises the raw materials, the process, and the whole supply chain’s completed goods. This would undoubtedly influence the efficiency and responsiveness of the supply chain if modifications in the inventory policies were made. As one of the drivers of the supply chain, inventory has to coordinate with other drivers so that the reactivity and efficiency of the supply chain’s performance are determined.

Inventory management is to deliver raw materials to the end consumers to control movement and flow across the supply chain. Inventory relationships with the supplier chain know how much time a product needs to flow to the end customer through the “pipeline.” The supply chain holds inventories to satisfy demand and supply uncertainties and discrepancies. Good supply chain management is achieved by integrating partner logistics business operations into the supply chain to ensure the coordinated flow and storage and the inventory management functional fields.

As it plays an integral part in the supply chain, it will always be hard for supply chain managers to manage stocks effectively. Managers should be in a position to have excellent inventory management for the supply chain. Managers should be able to take the decision-making processes in the supply chain to increase the supply chain surplus. One of these steps is the supply chain planning to predict inventory demand in various markets, including what inventory policies to follow. By anticipating demand uncertainty, companies can manage stocks in the supply chain.

Inventory also plays an important part in ensuring an efficient competitive supply chain strategy. The response of a supply chain might be affected by high volumes of inventory or less inventory. This is how the competitive strategy of a supply chain company is created.

Finally, efficient management of the supply chain may be done through good inventory management. In particular, to monitor inventory flow in the supply chain, both should be synchronized. Probably effective management of the supply chain would also exist if inventory was managed efficiently. They are interrelated, and if one does not coordinate with another, a company’s expectations and demands are not satisfied, affecting the company’s s profitability.

5. Trends in inventory management

It is vital to keep ahead of current trends in stock management regardless of the company. Many trends assist firms in analyzing where resources are being invested, while others will increase stakeholder buy-in, better use of data, and a plan for growth (Abby Jenkins 2021).

5.1 AGVs and AMRs

Customers want even speedier delivery, which means that companies are increasingly seeking more efficient ways of working. The AGVs and AMRs are instruments to aid warehouse operators in collecting items from the decks and pallets.

AGVs employ magnetic strips or wires to follow set routes around a warehouse, which means that the equipment that changes their floors or many people move around is not very suitable. AMRs are among the new class of “collaborative robots,” since they incorporate intelligent sensors, such as those used in self-driving automobiles, they do not need to rely on set pathways to sail space.

5.2 Artificial intelligence

In warehouses and inventory management, artificial intelligence (A.I.) and machine learning (ML) systems operate along with the projects of the IIoT. The difficulty is that much data manufacturers and retailers currently gather does not fit well into a tablet: Think about product pictures, movies taken as AMRs move about warehouses of different SKU types, and data generated by sensors and scanners of all sorts. In order to find inferior products or packaging, machine learning might be utilized to enable buyers only to obtain excellent products.

5.3 Cloud-based solutions

It may be a game-changer for every firm if the stock is tracked in real-time. Due to the ability of cloud-based solutions to securely, centrally, and anywhere access all data, decision-makers can respond rapidly to inventory problems and resolve them. Moreover, the cloud offers other benefits than on-site applications like software as a service: lowers upfront costs because no hardware can be purchased, faster deployment, up-to-date software, and greater security and resilience than most businesses can build on.

5.4 Distributed inventory management

Shopping in various warehouses may minimize travel and accelerate delivery times – when an organization can arrange the appropriate products in the right location and regularly ship things from the nearest warehouses to the consumer.

Success calls for data analysis to determine where orders come from and where the stock is situated, flexibility to establish distribution centers based on data at appropriate locations, and technology to instruct suppliers to break up shipments correctly.

5.5 Predictive picking

In this scenario, unstructured data are used to prevent behaviors by detecting interdependencies and patterns. This tendency again relies on data analysis. Predictive selecting software may enable companies to fulfill their orders before placing the purchase. Success depends on predicting client orders with a high degree of precision, for example, planned marketing campaigns, weather, and seasonality.

5.6 Success Strategies for Trend Adoption

For your company, which trends make sense? That relies on the strategic goals, money, size, and technological appetite of your firm. Some factors to consider while assessing a trend are presented below. Weigh cost/benefit against other prolonged, short-term, and media-based projects and verify that the Executive Sponsor successfully defines the strategy.

5.7 Personalization

Personalization in inventory management requires a comprehensive understanding of the buying practices of consumers so that businesses store and propose appropriate items and guarantee a smooth experience based on prior behavior. A sophisticated stock management system helps businesses to use customization information to improve sales. For example, a store might recommend extra things for consumers that browse or check. In contrast, a manufacturer may start producing supplementary items, such as maintenance kits for its manufacturing equipment.

5.8 Creative financing

The innovative funding used to pay for inventories can provide a competitive edge, particularly for young businesses. On the lesser side, think of sites such as Kickstarter, where a producer may rack up retail cash before the product is built. These sales can finance raw material acquisitions and production capacity.

More leading manufacturers might go beyond a traditional stock loan, where the stock itself is the collateral. Reduce invoicing expenses before searching for additional funding. A.R. credit or factoring, also known as invoice factoring, involves either bidding or selling outstanding A.R. to a “factor,” paying your business a percentage of the entire invoice value, generally 70% to 90%.

5.9 Automation

The automation process establishes workflow rules for companies that initiate specific actions without or minimize human involvement. By automating rotative tasks, an organization allows people to concentrate on more exceptional projects, including projects that encourage growth and improvement in product quality.

Automation of warehouses focuses on transferring merchandise into and around warehouses with minimum personal participation. It focuses double on physical and digital processes. The automation of warehouses combines machine training, robotics, and data analysis. An example is a warehouse management system that collects information about the number of SKUs shipped within 24 hours and directs a worker to choose all the products at once to prevent repetitive journeys. Further improved warehouse automation would let an AMR traverse through the warehouse and create an order without human aid using A.I., cameras, and sensors.

5.10 Third-party logistics (3PL)

3PL is where a third party is outsourced to distribution and storage or other activities. These services can enable companies to reach more consumers or function more efficiently without expenditure for infrastructure construction. Enterprises might outsource a whole logistics or unique operations process. 3PL is the key to successfully connecting all manufacturing locations, including the manufacturer and 3PL supplier, as a coherent supply chain.

More eCommerce signified an increasing profit drain, namely the reverse supply chain. 3PL contracting for returns might decrease costs since such companies tend to provide economies of scale, including better rates for carriers and systems tailored to carry out returns as cheaply and effectively as feasible.

5.11 Hybrid warehousing & shipping

A hybrid warehouse brings together several characteristics — storage, pick-up, transportation — and some not as usual, such as when the connection between retail and storage locations fluctuates. Some big-box retailers, for example, have converted space into drop-ships. While this effectively uses space, store workers may require retraining.

We also found merchants with those 3PL’s stockpiling and shipment orders to end consumers, adding a hybrid layer to conventional storage and shipping. Dropshipping, where retailers never own stocks but pay a manufacturer to send products directly to their consumers, may have a hybrid taste if a distributor decides to store a small number of popular items supplied to offer premium shipping choices. An innovative approach to warehouse management implies that companies may provide and decrease their expenses to this extra SKUs.

5.12 Omni-channel inventory control

Inventory control Omnichannel needs a coordinated operation of shops, distribution centers, and eCommerce to harmonize physical inventory and online stock to ensure pricing and discount or sales parity. A client buying a good for $50 online will take it, then decide to stroll around the shop and discover the identical item on sale at $39.99 and probably will not get in a happy line again.

5.13 Blockchain

A blockchain is a transactional database. Once transactions have been established, they cannot be changed, and everyone or a member of the private consortium has a distributed ledger.

There are numerous examples of firms adopting blockchain to manage and control inventories. Deloitte points out that 2020 marks the beginning of the blockchain decade and mentions a few creative instances which show the possibilities, such as companies that utilize the blockchain to secure A.P. loans. The best industry using blockchain is currently life and health, frequently for clinical studies and the digitization of health data. Walmart and Nestle are among the food distributors in the supply chain that utilize the IBM Food Trust blockchain to reduce food safety and freshness uncertainty and create efficiency throughout the supply chain to decrease waste.

5.14 Reporting & analytics

In real-time data analysis, to choose, build a customer-focused business model, decrease costs, and improve efficiency are familiar with many of these themes.

From a stock viewpoint, increasingly data-driven enables enterprises to predict better demand, refresh their inventory just in time, and get and provide almost-equitable updates on where and when supplies or shipments are located.

6. Conclusion

The management of inventories is one of the leading corporate logistics operations. Schonsleben (2000) says that inventory is one of the essential planning and control instruments for logistics because of its importance in commercial organizations. While the inventory of the work in progress has to do with the manufacturing process, it does not take extra value to make the physical stock or buffer storage store a waste of time and funds. Bowersox, Closs, and Cooper (2002) feel that inventory is usually the second-best component of transport logistics costs.

Inventory holding risks are increased by increasing the number of goods down the supply chain since the possibility to place the product wrongly or incorrectly grows, and expenses for moving the product down the canal have increased. Other hazards include obsolescence, pilferage, and damage, in addition to the risk of loss of sales resulting from inventories. There is no sufficient inventory.

Inventory is a significant asset in most businesses, according to Terry (2000). Therefore, efficient administration within the sphere of operations is a critical responsibility. However, it is not straightforward to control inventories. The several kinds of inventory and functions it offers entail a complicated set of considerations. Inventories are a product of an organization’s operational strategies and short-term and long-term purchasing, transactions, and sales choices.

For all manufacturing companies manufactured to completed stock items, optimum inventory management is an important goal. Inventories have a significant effect on the financial and economic success of the firm. Therefore, it is well recognized that an appropriate inventory management policy enables firms to attain better levels of profitability. Generally speaking, inventory management strategies should reduce holding costs through increased inventory rotation without generating significant inventories and back-orders due to peak demands and lead time delays (Bertolini and Rizzi 2002).

The attainment of the objectives of any organization is connected to functional goal relations. That is why inventory management strategy policies must be stopped or created to accomplish corporate objectives. An organization will grind to a standstill if it does not accomplish that.

7. References

Abby Jenkins. (2021). 14 Top Inventory management Trends to Know in 2021. Oracle NetSuite. (Accessed: 7^th August 2021). https://www.netsuite.com/portal/resource/articles/

All Answers Ltd. (2018). Inventory Management Literature Review. Retrieved from https://ukdiss.com/litreview/literature-review-on-inventory-management-with-practical-examples.php?vref=1

Balcik, Burcu & Bozkir, Cem & Kundakcioglu, O.. (2016). A literature review on inventory management in humanitarian supply chains. Surveys in Operations Research and Management Science.

Ballou R H. (2004). Business logistics / Supply chain management. Planning, Organising, and controlling the supply chain.5th edition. PEARSON-Prentice Hall.The USA.

Bertolini M & Rizzi A. (2002). A simulation approach to managing finished goods inventory replenishment economically in a mixed push/pull environment. Volume 15. Number 4.2002:1-2.

Biggart T B & Gargeya V B. (2002). Impact of JIT on inventory to sales ratios. Volume 102. Number 2002:1

Bloomberg D J, Lemay S & Hanna J B. (2002). Logistics. Prentice-Hall. New Jersey.The USA.

Bowersox D J, Closs D J & Cooper M B. (2002). Supply chain- Logistics management. International Edition. MC Graw Hill. The USA.

Braglia M, Grassi A & Montanari R. (2004) Multi-attribute classification method for spare parts inventory management. Volume 10. Number 1. 2004:1.

Chase R B, Jacobs F R & Aquilano N J. (2004). Operations management for competitive advantage. 10th edition. International edition. MC GRAW HILL. N.Y.

Clodfelter R.2003. Retail buying from basics to fashion 2^nd Edition. The USA.

Gourdin K N. (2001). Global logistics management. A competitive advantage for the new millennium. BLACKWELL Business. The USA.

Harrisson F. (2001). Supply chain. Management workbook. Butterworth / Heinemann. Great Britain.

Hugo W M J, Badenhorst-Weiss J A & Van Rooyen D C. (2002). Purchasing and supply management. 4th edition. Pretoria: J.L Van Schaik Publishers.

Monczka R, Trent R & Handfield R. (2002). Purchasing and supply chain management. 2 edition. South-Western / Thomson Learning. USA

Pycraft et al. 2000. Operations management. Southern Africa edition. Pearson education. South Africa.

Schonsleben P. (2000). Integral logistics management. Planning & control of comprehensive. Business processes. The St-Lucie Press / APICS Series.

Silver E A, Pyke D.F & Peterson R. (1998). Inventory management and production planning and scheduling. 3^rd edition. John Wiley & Sons. The USA.

Stock J R & Lambert D M. (2001). Strategic logistics management. 4^th edition. International edition. Marketing / Advertising series

Terry H. 2000. Operations management. Strategic context and managerial analysis. PALGRAVE.

Tersine R J. (1982). Principle of inventory and material management. 2nd edition. North holland.

Wild T. 2002. Best practice in inventory management. 2nd edition. BUTTERWORTH-HEINEMANN.UK.