Viewing window
A viewing window is generally a recess through which information can be viewed or work processes and procedures can be checked.
With a machine
When a work process is running, it may be that this or the machine functionality must be checked. For this purpose, viewing windows are used, which are often secured with glass panes , in dangerous processes also with armored glass panes. Such viewing windows can be found on petrol pumps, valves, milling and turning machines and oil reservoirs, among other things.
With the envelope
A viewing window in an envelope reveals the address field of the document inside.
advantages
All public information about the sender and recipient of the letter as well as further information for the processing of the letter by the letter service provider , the recipient's post office or the archive are applied in the address field of the document and are retained when the envelope is removed. The sender does not have to add this information to the envelope and can print and insert the document separately in terms of time, space and personnel from its creation.
disadvantage
A viewing window forms a mechanical weak point on the surface of the envelope and is therefore unsuitable for letters weighing over 500 g.
At ISO-TQM (Total Quality Management)
Used metaphorically, viewing windows in Total Quality Management (TQM) panels are a method used by companies to make complex relationships understandable and comprehensible to employees in production, office, administration and sales through visualization. Well-informed employees who feel that they are being addressed personally contribute actively to improving quality and results.