FlashlightAssemblyBy: Group 5Agacita, AngelicaPanes, Isabel FruileneMabasa, LanmarkAndales, Ian
Theoretical Background• There are three special interpretations that must beconsidered in the left-hand/right-hand chart as stated by Aft(2000). First is that the hands do not perform inspection.Second is that transportations are defined as movementsof the hands from one location to another location.Lastly, holds are considered to be delays.• There are factors or classification as well, to be considered inthe process of improving the productivity of the worker.These are the use of the human body, workplacearrangement and the design of tools and equipment.
• An ideal worker in the workstation must be productive asto keeping a sufficient amount of work. There must not bean idle time at all and everything has to be balance, thestarting and stopping times of the hands (based fromPrinciple 2 of motion economy principles).• Rhythm must be followed where there is a moderateflow of the worker’s performance because a slowing paceand speeding up makes the operator less productive(Principle 4).• According to O’Neill (2007), a machine is purely viewedas an overhead cost to the organization, not as apotential tool for strategic advantage.
• As the company reorganize, whether enlarging orreducing their work forces, the cost associated withhousing employees and providing their work toolscontinues to increase.• A research study made by Karasek and Theorell(1990) proved that an enhanced control over theworkspace and job control decreases or reduced therisk of stress on the workers. They also argue thatthat there are two significant sources of stress in thework environment; the way jobs are designed andthe design of work environments.
• In order to keep things systematized, these principles ofergonomics must be taken into consideration:• Principle 1- Work in neutral postures,• Principle 2 – Keep everything in easy reach, Principle 4 –Work at proper heights,• Principle 5 – Reduce excessive motions,• Principle 9 – Move, exercise and stretch• Principle 10–Maintain a comfortable environment• In designing a work station, it is important to know therelevance and taking into considerations the variations of bodymeasurements, whether you are designing for the average or the extreme.
• ISO defines usability as “The extent towhich a product can be used by specifiedusers to achieve specified goals witheffectiveness, efficiency and satisfaction ina specified context of use.”• dexterity or fine motor skills are thecoordination of the small musclemovements which occurs in the fingers,usually in coordination of the eyes.
MethodologyThe proponents made some observations in the processof the flashlight assembly. The data gathered were beinganalyzed and the weaknesses were being determined.Books were used as the secondary source for constructinga left-hand/right-hand chart. Only one person is beingconsidered as the performer of the activity. The chart wasconstructed as to the details of every operation. In which,the weaknesses gathered were the bases for generatingproposals for improvement.
Statement of the problem• The purpose of this activity is to assess the present method inthe flashlight assembly considering the 3 factors in improvingthe worker’s productivity where it also answers the followingquestions:▫ What are the unnecessary operations to be eliminated?▫ What are the sequences of activities that need to be changedor simplified?• Based on the findings of the study, what proposals could berecommended improving the existing method of flashlightassembly.
Objectives:• Investigate specific operations in order toimprove them by using operations chart• Eliminate all unnecessary motions and toarrange the remaining motions in the bestsequenceApparatus: Flashlight
PRESENT METHODWORK STATION DESIGNFINISHEDASSEMBLIESCASESBULBSREFLECTORSLENSESBOTTOMSCASESTOPSWORKER
WEAKNESSES:• Principle 1 – “The two hands should begin aswell as complete their motions at the same time”The present method failed to adapt the firstprinciple because the right hand did most of theoperations. It is seen that the there was atransportation made from the right hand to the lefthand, in which it is unnecessary. In result, the lefthand made most of the idleness instead of having afair routine in the operations.
• Principle 2 – “Motions of the arms should bemade in opposite and symmetricaldirections, and should be madesimultaneously”The present method failed to perform in thismanner since the left hand is in idle and doesnot permit the operator to work faster. Theremust be the same command for both of thehands in order to make the operations effective.
• Principle 8 – “Work should be arranged topermit easy and natural rhythm whereverpossible”Although, the operation permits the right-handed person to do the task, the location of thematerials are not appropriate for the right hand todevelop the certain habit. The rhythm of theprocess forces the operator to take the habitsinstead of allowing both hands to perform normally.
• Principle 9 – “Eye fixations should be asfew and as close together as possible”The distances or the arrangements ofthe materials make the method ineffectivein such a way that the operator tends tosearch for the next material. The operatorhas the tendency to get disorganize andinterrupts the normal motion cycle.
PROPOSED METHODWORK STATION DESIGNWORKERCASESBULBSTOPRINGSREARCAPSLENSESREFLECTORSFINISHEDASSEMBLIESDISTANCES FROM THE WORKER:FINISHED ASSEMBLIES -13 inchesCASES -6 inchesTEST JIG -4 inchesMAGNETIC HOLDER -4 inchesREFLECTORS -6 inchesLENSES -8 inchesBULBS -10 inchesTOP RINGS -8 inchesREAR CAPS -10 inchesLEGEND:-TEST JIG-MAGNETIC HOLDERHEIGHT OF THE TABLE: 3.01 ftVERTICAL CLEARANCE: 2.10 ftHEIGHT OF THE CHAIR: 2.04 FT4 ft3 ft
STEPS IN MAKING A TEST JIGSCHEMATIC OF THE TEST JIG1. Remove the HS-flat of the flashlight2. Connect the wire, black for negative and red for the positive to the HS-flat, thensolder.3. Connect the other ends of the wire, black for positive and red for the negative ofthe dry cell.4. Enclose the test jig with any recyclable case.HS -FLATDRYCELL+--+
Summary of the Left-Right Hand ChartPRESENT LEFT-RIGHT HAND CHARTLeft Hand Right HandTransportation Operation Transportation Operation1 3 17 21PROPOSED LEFT-RIGHT HAND CHARTLeft HandRight HandTransportation Operation Transportation Operation7 8 8 9
COST-BENEFIT ANALYSISTOOLS QTY COST (Php) BENEFIT*MAGNETIC HOLDER 1 849.25 The operator will no longer hold thecase of the flashlightTESTJIGHS-flat of the flashlightElectrical wire (3’ – blackand red)Dry cell (1.5V)Soldering wireSoldering iron1111120534349The dry cells will no longer be part ofthe operations, instead it make use ofthe testing of the bulb before the latterwill be attached to the reflector.1/2 x 4 x 8Plywood – ordinary(P170/pc)2 340Will be used to construct a table andchair in which it adds comfort and theoperator will have a chance to take arest after long hours of standing.2 x 2 x 10 – mahogany(P93/pc)4 372
COST-BENEFIT ANALYSISTOOLS QTY COST (Php) BENEFITCommon nails – 2”( 35 / kg) 1 kg. 35Will be used for constructing a tableand chairLabor for 1 day(305/day) 3 915TOTAL 2622.25* Total cost is subject to change due to shipping cost of magnetic holder, since itis made available in www.aircraftspruce.com
STRENGTH:• Principles 1 – 3: “Two hands begin and completetheir motions at the same time..Two hands shouldnot be idle at the same time..and Motions aremade in opposite and symmetrical directions”The proposed method used of the two hands inwhich the motions made fair distribution of theoperation. Although, there was an idle on the part ofthe left hand (in holding the lens) but the thought ofhaving both hands work simultaneously has been oneof the advantages.
• Principle 8 – 9: “Work should be arranged to permiteasy and natural rhythm..Eye fixations should be asfew and as close together as possible”The arrangement of the spare parts or materials forflashlight assembly is made closer in order to work easilyand to avoid stress on the part of the operator. Thedistances are as well made easy to reach and arrangedaccording to the sequence of the operation. On the part ofthe operator, he or she is not force to follow habits for thesake of symmetry since most of the operations are doneon the right hand, to compensate the right handed person.
• Principle 16–17:“The height of the work placeand the chair should be arranged..A chair of thetype and height to permit good posture shouldbe provided”Bad posture can tire the operator much morequickly than good posture. In which, tired operator isnot as productive as rested workers. Good postureis encouraged through the use of comfortable chairsallowing the operator to sit or stand.
• Principle 18-19:“The hands should be relieved of allwork that can be done by a jig or fixture..Two or moretools should be combined wherever possible”The added tools or fixtures eliminate the need for thehands to function as holding the materials and promotethe performance of simultaneous motions. It is veryimportant to respect the capabilities of the human since heor she is not automated. Providing the workstation withdevices that will help the operator, although it is costly,much make sense to what productivity is concern. Asstated by Aft (2000), use people where they are mosteffective and use machines where they are most effective.
CONCLUSIONUnnecessary movements cause delay and delay means additional cost.So, in this, unnecessary movements should be removed and that includesthe transferring of the material form one hand to the other and doing thejob one at a time where in fact the operator can do multiple jobs on thesame time. Distance traveled by the worker or the material really matters,the closer the distance of the materials from the worker is, the better itwould be and the process should be systematic in such a way that thematerials should be orderly sequenced by their use. The goal of this workis to obtain the best method to perform the operation and these include theperforming of two jobs at a time and letting both hands work beneficiallywith each other to minimize the time consumed in performing a job.
RECOMMENDATIONTo obtain the improvement goals, the researchersrecommend the company to apply the proposed methodwhich is the best possible method in improving theproductivity of the worker. The proposed method includes thearrangement of the work station putting the first material to beused on the nearest place from the worker followed by thenext material and so on. Also on the proposed methodsuggests eliminating the unnecessary movements whichcause delay. Management in imposing the proposed methodis advised and training the worker to be skilled on theproposed method is urged.