Taking the above points into account results in the green “effectiveness corridor” in Table 8, in which the right filling machines can be found. For example, 2,000,000 bottles could be filled without interruption at filler performance rates of between 18,000 bot/h and 40,000 bot/h. At performance rates below 18,000 bot/h filling would have to be interrupted for CIP/SIP, due to the limiting production cycle. However, a filler with a performance rate of 40,000 bot/h would not be used to capacity. The remaining time could be used for a further batch. If the same quantity is filled using a filler with a performance rate of 6,000 bot/h, production would have to be interrupted at least twice during this period for CIP/SIP. Small batches do not fully utilise the capacities of fillers with high performance rates. As a logical conclusion it can be said that an aseptic filling machine produces cost-efficiently when it is in constant operation.
Sub-aspects of maintenance include upkeeping and inspection. Upkeeping delays the wear of the machine. The inspection serves to ascertain and assess the actual condition, including determining the causes of wear and deriving necessary consequences for the future. Both are intended to ensure high availability of the filler. Both the inspection and the upkeeping are absolute prerequisites for reliable operation of aseptic filling systems.
As the product to be filled also enters into direct contact with moving machine parts, there is a risk of product residues in the filling system. These product residues can be the basis for microbial contamination in the filler. This risk can be minimised by regular cleaning and sterilising. Despite this, a CIP/SIP does not cover every area (for example behind/beneath seals). Technically it is only possible to develop a permanently sterile filling system with very high engineering and cost inputs. Even then it is not possible to guarantee that no contamination will occur. For this reason an examination for concealed contamination and existing product residues in the course of the servicing is to be recommended. That is why a microbiological assessment must always form part of the service.
Upkeeping and inspection should be joined up in so-called service modules. With respect to the microbiological safety, long time intervals between individual service modules are not to be recommended. A service module that is conducted once a year might satisfy all technical specifications, but will in no way guarantee microbiological safety. Microbial contamination of an aseptic filling system often does not become noticeable within a few hours or days, but may only become apparent after a few weeks in the form of returns from sales. In many cases this leads to shutting down the filler. The search for the source of the germs costs time and money. Even if it were easier to plan conducting one or two major maintenance operations a year, this would not take into account the microbiological risk. Small preventive service modules conducted at shorter intervals increase the microbiological safety. If the annual time input for one to two major service modules is compared with the time input for a number of small service modules, there is hardly any difference. Ultimately the risk does not lie with the machine manufacturer, but with the operator. The question therefore arises as to whether forcing long maintenance cycles actually represents technological progress.
Upkeeping and inspection are among the most important secondary times for a permanently functioning aseptic filling system that need to be taken into account for designing the capacity. For organisational and economic reasons both should be carried out at the same time. Admittedly this makes production planning more costly, but unscheduled downtimes can be avoided in this way and scheduled downtimes shortened. Unscheduled downtimes cause costs and lead to loss of time and thus have a direct impact on the effectiveness of an aseptic filling system.