Procedure and Process Optimization at Workstations for Optical Final Testing of Clock-Faces
Background / Objective
Numerous factors can influence testing results of working persons; hence work processes can be ergonomically organized, for example surrounding conditions, reaching and viewing distances, structuring of working time, or difficulties at testing tasks. An inadequate work design can lead to e.g. inaccuracy of testing results, to a decrease of reliability and process quality, or to an increase of time need, dissatisfaction, or psychic satiation.
Present work stations for the testing of clock-faces for car cockpits should be ergonomically redesigned concerning workplace, working space, and testing tasks.
- Improvement of ergonomic conditions at testing workstations
- Reduction of workload
- Improvement of test results
- Reduction of required space
The project is classified into four modules:
Workplace design includes the ergonomic adjustment of shape, physical dimensions, and relative arrangement of single elements of the testing workstation (such as desktop, support surface, and work equipment). In particular the size and range of body as well as function areas (e.g. reaching and viewing distance), internal and external dimensions should be taken into consideration.
First a model workstation will be developed, set up, and modified in respect of ergonomic recommendations as well as company and workplace specific demands for a redesign of the current testing workstations. At this it is important to include the experience and know-how of employees. On the one side it supports the acceptance of the future workstation by them and on the other side necessary modifications of the future workstation are introduced early. The developed and realized model workstation should be used by several employees. Ergonomic aspects are used to assess the workstation, such as the quality of testing results, the observation of employees by ergonomically trained persons while they working at the workstation, and the evaluation by the employees themselves. Several necessary modifications can be conducted during this process.
Module 2: Work space design
The following aspects are ergonomically necessary for the optimization of the work space design concerning functional spatial planning:
- Collection of surrounding conditions, such as climate, noise, and illumination (current status analysis)
- Collection of workflow and information flow (current status analysis)
- Collection of work and communication relationships (current status analysis)
- Collection of suggestions about required space, staff requirements, required floor space, required store place (target state analysis), taking into account of
- the manipulation surface
- the access and movement space
- the communication and escape route
- the minimum airspace
(Cf. German Workplace directive 2004)
- Set up, schedule, and regulation of optimal possible operation sequences (e.g. action chart) (target state analysis)
- Planning of functional and ergonomic furniture, this aspect overlaps with module 1 “workplace design”
Module 3: Testing task
The following aspects are relevant for the testing task
The difficulty of testing task is determined by the number of testing characteristics and possible decision making. Hence the number of concurrent testing characteristics, which should be identified and respond to, is reduced to a minimum. Similarly the possible number of decisions and classification of defective particles should be reduced as well.
The kind of communication during the testing (inspection or tolerance testing) is a further influence on the difficulties during testing.
The difficulties of testing tasks can be ergonomically designed, for example by parameters of fixed testing criteria as well as the arrangement and structure of the testing characteristics.
Ergonomically poor posture at optical testing procedures can lead to an increase of physical workload and absence of work rates (cf. module 1). Another important aspect is the visual conditions that should be considered because the eyes are a crucial factor for the visual testing task (cf. module 2).
The current testing task is characterized by monotony and possible reduced vigilance.
The testing task and quality of testing still depends on working time. Therefore it is important to bear in mind the duration of working time, the schedule and the break regulations. In particular the rest break schedule should be considered, because research on vigilance shows that the performance capacity declines after a 35 to 45 minute-long continuing testing task and declines even more with proceeding endurance of the task. This decrease of the performance capacity cannot only be countered with short breaks, but also by performing other tasks.
Finally, the testing persons themselves are no marginal influence factors at all. Hence there are in particular personal characteristics, or attitude towards job and job qualification.
The factors of “poor posture” and “visual conditions” are considered in module 1 and 2, therefore module 3 investigates the following aspects:
- difficulty of testing task
- monotony / vigilance
- working time
- testing person