Classification, functions and types of warehouses

The primary function of a warehouse is to store goods. However, it should be remembered that, in fact, the functions of a warehouse today are not limited to storing selected items. Their purpose is also to create the right conditions that are necessary for the proper operation of the entire “organism”, which is undoubtedly the warehouse.

What is a warehouse and what are its tasks?

The definition of what a warehouse is is quite simple. Well, it is a space in which certain storage and logistical processes take place. The former definitely include the ability of a given facility to store a selected assortment of goods. And this means that the selected facility has the infrastructure necessary to maintain the appropriate conditions in the facility, viz:

• air temperature,
• cleanliness,
• humidity.

In turn, speaking of logistical processes, we mean the organization of loading or unloading, intra-warehouse transportation, keeping (compiling) relevant documentation, providing ICT networks, as well as securing the building from outside interference.

What does a warehouse consist of?

The construction of a warehouse depends on its purpose, technical capabilities, but also on the infrastructure inside and… its dimensions. This means that if we want to define it, we need to use dozens of variables. Harmonizing, a typical warehouse consists of:

• an entrance and exit gate,
• the space necessary for maneuvering vehicles and controlling their contents,
• the warehouse receiving area (this is where loads are received),
• release zone (this is where cargo is released to the outside,
• warehouse area, where storage of goods in the warehouse takes place,
• storage areas where stored articles are segregated,
• offices, where the organization of warehouse work takes place.

In addition to this, the warehouse also has rooms of an auxiliary nature. The tool room (where the warehouse equipment is located), the social space and the security and monitoring center (the headquarters of security personnel) are just a few examples of places whose presence is necessary for the proper functioning of a large facility.

Types of warehouses and their classification

The classification of warehouses is a very complex subject, which must be defined in light of many variables. Below we will present the most common types of warehouses in the Polish logistics space in relation to specific factors.

Classification of warehouses by design

An open warehouse is a space that is basically a paved yard designed to store weatherproof cargo. Open warehouses are used to store firewood, wood, some trim, and building materials, among other things.

A semi-open warehouse is a covered space (such as a shed), the interior of which is enclosed by a maximum of three structural walls. Goods in semi-open warehouses are protected from rain, snow and the sun’s intense rays, but at the same time have access to fresh air at all times (e.g. cement, chemicals for ice removal, etc.).

An enclosed warehouse is a separate space that is built of durable building materials and is also permanently connected to the ground. The goods located here are completely protected from external factors, and if necessary – thanks to the appropriate infrastructure – it is possible to create an appropriate microclimate in them.

Special warehouse – is a place where goods that require the undertaking of appropriate safety procedures are stored. For example, special warehouses store gases and liquids with strong explosive properties, medicines or bulk goods that require an appropriate microclimate.

Division of warehouses by type of stored products

The division of warehouses by the type of goods stored in them divides them based on the characteristics of the goods stored inside.

• Warehouses storing cargo units, i.e. pallets, Euro-pallets, crates, containers, as well as goods placed on pallets.
• Warehouses storing bulk goods, where the assortment is stored in bulk, such as using silos or other high-volume containers.
• Warehouses storing gases and liquids, which are placed in special containers.

The classification of warehouses on the basis of the products stored also makes it possible to separate two distinct categories of warehouses, which are defined on the basis of accessibility to the loading unit. According to this division, we distinguish:

• warehouses with direct access, where goods are available, for example, on appropriately designed racks,
• warehouses without direct access, where the goods are located on satellite racks.

Division of warehouses by function

Warehouses are also divided on the basis of what function they perform and – consequently – what their place is in the logistics supply chain. According to this division, we distinguish warehouses:

• production, in which cargo is stored at intervals, that is, only when one stage of production ends and another has not yet begun,
• transshipment, in which storage space is used as a distribution center, thanks to which the costs incurred by companies are significantly reduced,
• distribution, which act as delivery or shipping warehouses, as their primary task is to create new routes for the flow of goods,
• commercial, which serve retail or wholesale outlets,
• supply stores, whose task is to meet the needs of the stores and wholesalers served,
• customs, which are used for temporary storage of goods subject to customs duties (e.g., from outside the European Union),
• consignment, where goods are in the custody of customs, but are still owned by the supplier,
• containerized, where goods are stored and handled inside containers,
• factory warehouses, where cargo necessary for the operation (sustaining production) of a work plant is stored.

The functions of warehouses can be very complex. This means that a commercial warehouse can simultaneously play the role of a supply warehouse.

Classification of warehouses based on the manner of distribution of goods

The basic way to classify warehouses based on the way the goods are arranged is the height at which the stored goods can be stored.

• Low storage warehouse – is a space whose usable height is less than 4.2 meters.
• Medium storage warehouse – is a separate space, the height of which oscillates between 4.2 and 7.2 meters.
• High storage warehouse – is a building whose height oscillates between 7.2 and even 25 meters.
• The second and third groups often include multi-story warehouses, which have two separate working levels (for example, first floor and mezzanine).

The storage methods adopted depend primarily on the design of the chosen warehouse, how its space is used, and the purpose of the building. The storage methods introduced may also depend on what type of goods are stored in them.

Division of warehouses by their location

The central warehouse is the place that plays a dominant role in the selected supply chain. This means that this is where all cargoes go and from there they are dispatched to subordinate regional warehouses. Only their task is to meet the needs of local sales centers, such as supermarkets, wholesalers, etc. Smaller warehouses can be used by small retail chains. These include, for example, shipping warehouses.

Division of warehouses by degree of mechanization

Warehouses can also be divided based on the technological solutions used in them to improve the handling and loading of goods.

• Non-mechanized warehouses – are facilities in which the vast majority of warehouse work is done manually. Today, in the era of increasing automation, they are rare on the logistics map of Poland. In principle, we can include in this group only small factory and store warehouses.
• Mechanized warehouses – these are facilities in which most of the work related to the receipt and release of goods is carried out with the help of machines. Mechanized warehouses are the most common in Poland. Mostly warehouse equipment, that is, trucks and forklifts, are used to operate them.
• Automated warehouses – these are buildings in which human participation is limited only to overseeing the entire process of loading and unloading goods. Automation also includes the processes responsible for identifying the goods and managing them in individual warehouse zones.

Division of warehouses by loading method

The last criterion by which warehouses can be classified is the method of loading, which results from the design of the facility, as well as the way the ramps are arranged.

• Warehouses that allow loading and unloading in reverse – these are facilities in which the dock of the ramp is adjusted to the height of the car trailer. This makes it easy to export, for example, cargo placed on pallets, using manual and electric palletizers or forklifts.
• Warehouses that allow loading and unloading along the side – these are facilities where the ramp design only allows loading or unloading along the side plane. These warehouses are equipped with a so-called zero gate, through which forklifts pick up the cargo from the trailer.

As you can see, the division (classification) of warehouses from the technical and organizational side is a very complex process. The same is true for the construction of such facilities, the structure of which must be strictly tailored to the requirements of the customer. The use of steel structures in hall construction allows you to modify the project practically at will, so that you can take into account such factors as local conditions in its outline.

If you are interested in designing and building storage halls with a structure tailored to your needs, we invite you to contact us. Our goal is to create a solution that satisfies the customer.