3.C Material flow, personnel flow and layout

Here you will find answers to the following questions: What is the significance of the personnel flow and material flow in production? Which principles governing the material flow are applied in pharmaceutical production?

3.C.1 Material flow

Material flow refers to the interlinking of all operations relevant to sourcing, processing and treatment, as well as the distribution of material goods within specified areas. This specifically involves: processing, handling, transportation, testing, stopovers and storage. Material flow is the sequence of individual manufacturing and storage steps, starting with the raw material and ending with the finished product. In addition to economic considerations, the material flow has a particular significance in terms of Good Manufacturing Practice.

Figure 3.C-1 Functions and characteristics of material flow

Functions and characteristics of material flow
Functions Suitable for preventing the omission of quality-determining manufacturing and control steps Prevention of confusion Compatibility with other manufacturing procedures in other rooms
Characteristics Clear Unambiguous Crossing-free Characterised by short routes

The material flow ultimately represents the manufacturing process in the building which must be broken down into individual steps and presented in a flow diagram. Each processing step must be assigned to a machine, and each machine assigned to a room. The rooms in the building must then be grouped in a manner that reflects the material flow.

There are two main principles governing the material flow that will obviously be influenced by the building structure as well as the products: these are the horizontal and vertical material flow.

Figure 3.C-2 Illustration showing the principle of vertical material flow
[Pohal, 1999]

The horizontal material flow is determined by the transportation of materials using conventional methods. Production takes place at one level, or several levels connected by lifts. Transport and production take place at the same level. The horizontal material flow is widespread in the case of sterile dosage forms and in solids production.

A vertical material flow, implemented for the first time by Prof. Lhoest, involves the specific use of gravity for the transportation of products. The production equipment operates at several connected levels. Transport and production take place at different levels wherever possible. This procedure is mainly used in solids production (see figure 3.C-2).

In addition to the two main principles of material flow described, an interlinking of facilities is desirable from the GMP standpoint, particularly for vertical material flows but also for horizontal material flows. The facilities are joined together using fixed connections such as pipes, tubes, coils, etc. The product may be transported from one machine to the next via these connecting elements without having to be transferred to intermediate containers (see figure 3.C-3).

Figure 3.C-3 Illustration showing principle of interlinked material flow

A comparison of the aforementioned principles of material flow is shown in figure 3.C-4.

Figure 3.C-4 Comparison of principles of material flow [Pohl, 1999]  

Comparison of principles of material flow
	Advantages	Disadvantages
Horizontal	No connection with other levels Clear production sequence Simple tried-and-tested transportation systems	Large hygienic areas Transport and production not separated Transportation systems (stackers) often not compatible with GMP
Vertical	Transport and production separated Small hygienic areas High degree of automation Closed systems	Technically complex Greater need for validation No visual check possible Special architectural design required Complicated cleaning process
Interlinked	Flexible transport Closed systems to a large extent Can be automated	Large hygienic areas Transport and production not separated Technically complex

3.C.2 Personnel flow

Many characteristics and functions of material flow also apply to personnel flow. Most importantly, logical organisation of the personnel flow serves to protect the product in addition to considerations of economy and labour legislation.

Figure 3.C-5 Functions of the personnel flow

Functions - personnel flow
Support of zonal concept Prevention of cross-contamination Product and personnel protection Economic efficiency

To optimise the material flow, the appropriate number of persons required to operate, monitor and maintain the machines and facilities must be determined. The functions of individual persons must then be described and the routes transferred to the layout. The personnel flow and its iterative optimisation are assessed together with the layout and material flow based on the following assumptions:

• Access to pharmaceutical areas only via locks/changing rooms
• Separate routes for pharmaceutical and non-pharmaceutical personnel
• Short routes

3.C.3 Layout

"Layout" refers to the visual representation of machines inside rooms and also the arrangement and shape of rooms within a building. When finding a suitable layout, personnel and material flow are also factors to consider in addition to the necessary areas or volumes and room planning. The layout shows functions that ensure a safe manufacturing process and so when designing the layout it is recommended that quality assurance is also considered. Figure 3.C-6 shows the information that can be read off from the layout

Figure 3.C-6 Layout information

Layout information
Type and size of rooms Room layout and arrangement of machines Traffic routes (personnel flow and material flow) Locks for material and personnel Staff rooms (short break areas, toilets) Zone classification

.

Summary Material and personnel flow influence GMP and the economic efficiency of an operation. Horizontal material flow is predominantly used in the pharmaceutical industry, though examples of vertical material flow are becoming increasingly common - particularly in the production of solid dosage forms. It is recommended that quality assurance is also taken into account when determining the layout.