April 10, la21 



HARDWOOD RECORD 



19 



Motion Study as a Basis of Correct Cost 



By J. C. Bohmker 



Manager of David Bradley Mfg. Works, Bradley, III. 



(Continued from March 25 issue) 



Description of Wowk 



There are many wage payment plans in operation, but the one 

 we shall deal with is straight piece work. The time study remains 

 the same in all cases. If once the correct production value, or time, 

 is established, any payment plan can be applied. The writer has 

 used many different plans, but after some years of operation of the 

 several plans finds the straight piece work the most convenient on 

 account of its simplicit.y of operation and the ease of application by 

 the worker. The premium or percentage plan of payment, as a 

 rule, is looked upon with suspicion because of the mathematical cal- 

 culations involved. The workman feels that because of his in- 

 ability to follow the method of conclusion, the whole thing is 

 humbug and merely a means of fooling him. The straight piece 

 work plan, if properh' applied, will yield excellent results and 

 makes for nonfluctuating costs. Once piece work is established 

 on all piece parts and assembly operations, material and overhead 

 must be kept with- 

 in maximum limits. 



The woodshop 

 department has an 

 order to make a 

 certain quantity of 

 piece part No. 

 6500-A; it is found 

 that no piece work 

 price on tenoning 

 operation No. 5 is 

 in force. The piece 

 work rates depart- 

 ment is notified 

 that a price on this 

 operation is 

 wanted. The rate 

 setting depart- 

 ment, with the as- 

 sistance of the 

 foreman, lays out, 

 or plans, for the 

 best method of 

 handling the work. 

 A sketch is made 

 as required, in 

 space provided on 

 time study or ob- 

 servation sheet as 

 a reference for the 

 next setting up 

 should there be 

 something partic 

 ular or out of the 

 ordinary about the 

 operation. As in 

 the case of the 

 part in question, 

 some support must 

 be provided to pre- 

 vent tenon break- 

 ing out. 



For convenience 

 of comparison, we 

 show on Fig. 8 



OPERATION NO. 



OPERATION 



Tennon 



TIME STUDY 



DEPT. 13 MACHINENO. 415 IMPLEMENT TStl C - ModCl "S" 



NAME OF PART 



Leg 



to pr event breaking out. 



Component 

 Time (Lost 

 Motion 

 Elininated) 



DETAILED OPERATION 



2 Screw down clamp 



J 3 Pasa ovfii_ 

 ' - Return 



tennoner 



8 Remove 



« Lay pnjtrup)^ 



froa claap 



Time f Total Min . Time .4685 Min. + 25^ 



For 

 Comp. 

 Oper. J 



Standa rd Time .5856 Std. Time 



Std. Time_Eer _Ec^.^QCSaJlra^ 

 I QO .98 Hre. 



(In- MZ5$ toxjt. 

 clxxdind Tot. P.ff. 

 Loet I .394 , 



Motion )V. .831 



The diff. between 



.345 



Time 1.225 Hrs. 

 47.5Jt 



-f 439fc PIECE WORK 



Std. com- 

 ponent time and comp. oper 

 time indicate* lost motion, totai. piece work time 



BASE RATE % , fiQoPERATOR 



BASE RATE S 



.50me 



BASE RATE < 



APPROVED. 



M«i8 SM 10-20 F^. P. 



(Time Study Sheet) the component time of the operation, also the 

 time of complete operation. The component time is the time ac- 

 tually required to pick up the piece from truck, lay on table, next 

 screw down clamp. The operator may perform some unnecessary 

 motions between the time of placing the piece on table and screw- 

 ing down clamp; no note is made of this motion or time, the object 

 being to determine the minimum time. We pass on to next motion 

 and so on until operation is completed, noting the time by stop 

 watch, making as many observations as may be considered neces- 

 sary on the individual motions to arrive at a fair average for each. 

 We then add the minimum time. The total thus found is not the 

 time the operator can maintain, but it represents the true produc- 

 tion time with all losses or waste motions eliminated. 

 Influence of Kind of Work 

 It depends entirely upon the nature of the work as to how much 



of the minimum 



PIECE PART N O 6 500A timc the operator 



can maintain. So 

 we make a careful 

 analysis of the 

 machine and ma- 

 terial to be han- 

 dled, and from 

 this are able to es- 

 tablish some rela- 

 tive factor which 

 must be added to 

 the minimum time 

 so that he can 

 maintain a steady 

 production, with- 

 out undue fatigue. 

 This factor we 

 shall name "fa- 

 tigue factor." It 

 changes with the 

 different opera- 

 tions and materi- 

 als involved. For 

 the operation un- 

 der discussion, we 

 have adopted 25 

 per cent, which 

 represents a fair 

 average for this 

 particular kind of 

 work. One may 

 find in some in- 

 stances that the 

 fatigue factor will 

 vary from 15 to 50 

 per cent, depend- 

 ing, as already 

 mentioned, on the 

 class of work, ma- 

 terials and ma- 

 chinery. The ad- 

 dition of the fa- 

 tigue factor to 

 the minimum time 

 in minutes rep- 

 resents our new 



Stamdard Production Per Hour 1 SQ Pea. 



The xrork amat be eupported at point marked "W" 



Pick up piece from trucks lay on table 



total minimum time per pigCE IN min. SlSSi-t- 25 *' 



standard time per piece in 



standard TIME PER PIECE IN MOURq 



STANOAHD Time Per 100 Pieces IN HOUR» 665 



IN HOURS 



\H HOURB 



.025 



,1225 



.050 



.020 



.080 



.021 



3961 



00665 



lee. 



83JL 



77f-9 



