Whisky carton assembly
This case study shows a worker assembling a carton, using a glue gun to attach the base to the carton. Before reading this, it may be useful to read the "try it out" overview if you have not already.
Task description
- The worker assembles a card carton. The worker picks a flat card, opens it up, places it on a form, and then uses a glue gun to attach the base to the carton.
- The worker repeats the task about every 10 seconds. The worker sets their own pace of work and reports they do not have difficulty keeping up with the work.
- The card weighs less than 1 gram and the glue gun weighs 66 grams. There is no indication of any particular force required.
- The shift pattern is 07:00 – 19:00 with a one hour break at 13:00 and two 30 minute breaks at 09:45 and 16:30.
- The task is carried out daily.
Scores
Hover over individual rows for an explanation of each risk score.
A1. Arm movements
There are regular arm movements with some pauses.
The right arm has fewer pauses than the left arm so the right arm was given the slightly greater score of Amber 4.
A2. Repetition
The task repeats about every 10 seconds, but there are two or three similar motion patterns during each cycle (eg the right hand reaches to the right both to pick up the cardboard sleeve and the glue gun). For this reason, an Amber 3 is scored.
B. Force
The cardboard sleeves and glue gun are very light, and there is no indication of any particular force required.
C1. Head / neck posture
The worker's head/neck is bent for part of the time when looking down to glue the bottom of the box.
C2. Back posture
The worker's back is in a neutral straight posture with no significant leaning, twisting or stooping.
C3. Arm posture
The right elbow is raised to about chest height for a part of the time, when lifting the card from the box and, at times, when gluing the end of the carton.
The left elbow is raised to chest height for a part of the time when lifting the carton from the form and placing it on to the tray.
C4. Wrist posture
The right wrist is bent and deviated for a part of the time when using the glue gun.
The left wrist is bent back for a part of the time when picking up the assembled carton and placing it on the tray.
C5. Hand / finger grip
The right and left hands use a combination of pinch grip and wide finger grip for a part of the time, when handling the card.
D1. Breaks
The longest duration of work without a break occurs between 10.15 and 13.00. This is greater than 2 hours and so the score is Amber 4.
D2. Work pace
The workers set their own pace of work and report that they do not have difficulty keeping up with the work.
D3. Other factors
The work is carried out in a well lit environment and there are no other factors report ed.
Task score
The task score, calculated for each arm separately, is the sum of the scores of all the risk factors.
For example:
3 + 3 + 0 + 1 + 0 + 2 + 1 + 1 + 4 + 0 + 0 = 15
D4. Duration multiplier
The task is performed for 10 hours per day and so the duration multiplier is 1.5.
Exposure score
The exposure score, calculated for each arm separately, is found by multiplying the task score by the duration multiplier.
For example:
15 x 1.5 = 22.5
The exposure score can be interpreted using the table of exposure levels.
Possible solutions to consider
Automation and mechanisation
It is likely that this task could be automated. However, this may not be a cost-effective solution if there is not a sufficient return on investment.
Reduce exposure
Job rotation or job enlargement could reduce workers' exposure to the risk factors identified in the assessment.
Improve posture
Reduce awkward reaching by bringing work pieces closer with the use of a rack or shelving and reduce awkward wrist and hand postures by improving access to the work pieces. For example, it's estimated that the worker performs 7,200 reaching actions each day just to pick up and put down the glue gun on the table.
Thus even minor improvements to how the glue gun is accessed could have a considerable effect on both work demands and productivity.