Work Measurement
Ability to measure work is important for operations management. Methods study seeks improved methods and in the search for continuous quality improvement every member of the work force can be a methods analyst. This is the Toyota/Japanese, TQM/quality circles way.
Data on how long it takes to do a job is important for:
- contract estimating - how many staff hours are needed
- costing - what are the staff costs for a project
- facility planning - translating sales forecasts into production or service plans i.e. assessing system capacity (machines and people capabilities).
- scheduling and balancing -capacity and work content data is needed to calculate loading and improve balances
- rewards - measured work payment (bonus) schemes in manufacturing are fewer today compared to the 1960's and 70's but they do still exist (measured day work). Even without work measured rewards system, the availability of such data helps with proper evaluation of job loading. Has a member of staff got too much work physically to do? Can it be done in the time available or will it just pile up affecting employee motivation or stress and leading to operational inefficiencies.
Quality of Working Life and Ergonomic Issues
In the mid-1990's policies making organisations "lean" are, allegedly, requiring staff to take on more work (job enlargement) at the expense of the quality of working life. The employer-employee relationship at law places many obligations on employers for the health safety and welfare of their staff and the general public who are exposed to the activities of the work enviroment. If job overloading results in physical and psychological health risks such as back-strain, repetitive wrist injury and breakdowns due to stress then action is needed. There is no reason why work measurement data should " enslave". Informed analysis and problem solving in these areas "should" after all enhance the quality of job structures.
Work measurement
- involves assessing the TIME it should take to do a job with steps similar to method study: select, record, analyse, calculate and agree the task and its related time. We seek to determine the time for a qualified worker to do a job at a required level of performance.
"Qualified" means
- specifying the worker's characteristics and competences
- the job/task is stable and known
- we understand the characteristics of performance (the quality standard required, the quantity of work, the safety and other regulative aspects, the methods, equipment, materials used and the working conditions for performance).
Performance reflects the work rate or rate of output - in the defined working period (a day, a shift etc). It is sensible that performance standards are set at a level which can be reasonably achieved by a qualified and "motivated" worker (someone who wants to do the job, who is able to do it and who feels that the rewards - tangible and intangible are equitable to them).
The Basic Steps
The industrial engineer observes work and records times (stop watch or synthetic time data) and from this calculates basic and standard times. The steps involve:
- decide the task(s) to be measured and understand the work/task cycle including the start up, perform and wind-down/put away phases
- identify the elements of each task
- observe the task being done (reliable, sufficient, valid observations).
- record (stop watch and time sheet) the observed times for each element in the task cycle
- calculate basic times for these (average the observed times).
- add defined percentage allowances to each element to the basic time
- appraise the observed performance and give a rating. Apply an effort/performance rating as an adjustment to each element and then total.
Alternatively we can first total these basic + allowance element times and then apply a performance rating percent to the whole.
Accuracy
The accuracy needed in work measured data will vary according to its usage. Translating sales forecasts into manufacturing requirements planning calls for aggregated data e.g. machine hours for G-type parts, staff hours to produce a sub-assembly of type-K etc. However job/time data for a payments scheme which relates operative actual performances to their pay packet, must be more detailed. The employee will be very sensitive to data inaccuracy when their incentive pay is calculated.
Work measurement has problems of
inaccuracy, subjectivity, variety, human variability and averaging. Performance rating (is an operative working with an acceptable level of effort?) is subjective and prone to analyst inaccuracies.
References
Maintained and developed by C Jarvis