(b) Time studying with modern technologies
This technique applies the same criteria as the previous one, the only difference being that time observations are performed through video recordings, appropri- ately positioned and remote controlled, allowing for the simultaneous measuring of more operations related each other from different points of view.
Using specific software, by watching these video clips it is also possible to emulate normal working speed and introduce the right adjustments on measured times.
Like the previous example, this technique requires informing the observed workers, and pointing out the targets of the analysis so as to obtain their collaboration.
The advantages of the stop-watch study technique are:
• an opportunity to observe simultaneous correlated activities performed by more workers;
• an opportunity to watch and discuss the records with the workers, involving them in the improvement of manufacturing engineering;
• precision in observing operations deployed in multiple phases, with long times, as process auxiliary operations (changeover, set-up times, preventive mainte- nance interventions…);
• the analyst’s continuous presence is not necessary during video recording;
• an opportunity for analysis of the video clips by modern specialists (manufac- turing engineering technicians, ergonomists, safety and environment experts…).
This technique is widely applied in Japan and has even begun to spread through other industrial realities.
(c) Analysis with pre-determined standard times
Methods Time Measurement technique (MTM) began in the first half of the last century, spreading out through industrial manufacturing compartments, first in the United States and then in Europe. It consists of preventive analysis that allows quantifying the time necessary for each working micro-phase included in the operative cycle. Measurements are performed in office and are very precise and objective, because they are based on a wide range of elementary statistical data (standard micro-phases of manual work). Application requires significant effort in terms of analyst technicians, with high cost and long elaboration times. For this reason, the MTM technique fits with a widespread number of repetitive operations.
Other simplified techniques have been derived from MTM, integrating more MTM micro-phases, such as MTM-2 (still used in North America), UAS, MEK, TMC and, more recently, WF, developed in Europe and adopted by different manufacturing industries. The trend is to uniform all of these techniques through ISO.
Pre-determination of working times requires a detailed analysis of operative methodologies, defining the operation time-sequence diagrams in the designing phase of the project, while also taking the positions of equipment, machines, tools and each material handled during production into consideration. So it is necessary
to design the technological layout, defining exact working conditions and action range for the workers, according to what was defined in Sect. 3.1.
Pushed by the European Community, recent new criteria for risks resulting from working efforts, working positions and movement repetitiveness during the working shift (OCRA evaluation method) have been defined. To satisfy the rules, and improve productivity at the same time, it is very important to apply virtual analysis techniques, with particular attention to the most critical operations, so as to optimize workplace ergonomics and choose the best-fitting partner tools.
ERGO-UAS and EAWS, recently refined, are the most known standard applica- tions for time measurement that combine ergonomics standards to MTM prede- termination of working times techniques.
The analysis of working means and material handling containers is also very relevant for manual picking operations.
It is also important to adopt, during the development phase, product and process solutions convenient for assembling operations, with the target of reducing physical effort and avoiding human errors (design for assembly).
(d) Instantaneous Observations Analysis
Let us discuss this analysis technique, taking into consideration that it is only fitting for auxiliary operations, including office operations.
It is necessary that the analyst have a thorough understanding of the functions and roles of the observed employees. He performs periodic inspections in the relevant areas and by a route established by statistical method, so as to cover all workplaces. During inspections, he must instantaneously evaluate:
• if workers are at their designated workplaces;
• if workers are active;
• type of operation performed;
• type of tools used.
In collaboration with the foremen, the analysts classify activities by:
• types of activity, in relation to operative role assigned;
• utilization of technical support (working means, ICT supports…);
• time required for meetings, consultations or other activities not strictly neces- sary for the operative roles.
Processing data observed, by statistical method, it is possible to define roughly:
• medium degree of activity;
• activities composed by typology;
• time necessary for meetings and consultations;
• degree of utilization of technical support.
Consequent to this analysis, foremen have the necessary elements for deciding:
• the refinement of assigned tasks;
• improvement of working means and workplace organization;
• improvement of meetings and consultation management;
• the adequate amount of staff to assure service level and reduce inactive time.
The results of these instantaneous analyses can be directly adopted by depart- ment managers, even in a non-analytical way, to improve organization and the balance of work. For this purpose, it is also important to analyse interactions between different departments operating in the same organizational process.