SIMO (Simultaneous-Motion Cycle) Chart: Meaning, Method to Improve and Construction

SIMO (Simultaneous-Motion Cycle) Chart: Meaning, Method to Improve and Construction!

"SIMO" is the graph of the simultaneous movement cycle. It is one of Gilbreth's micro motion study and it provides the separable measures of each relevant operator's limb under research graphically. It is a very comprehensive graph of left and right procedure.

It simultaneously records the different therbligs performed on a common time scale by different parts of the body of another operator. The motions are registered in "Winks" (1wink= 1/2000 minute) against moment measured. These are registered by a "Wink Counter" placed in such a place that during the filming process it can be seen swinging.


Improving the present method:

Critically examine therbligs in the SIMO graph to investigate the option of:

(i) Removing or eliminating unproductive therbligs such as finding, selecting and avoiding error, etc. 

(ii) Re-sequencing of efficient therbligs such as assembling and disassembling, etc. 

A micro movement research sheet or a left-hand-right diagram is shown in Figure. 4.12 For the information below.

Operation: Finish hand filing copper work piece.

Time for searching, lifting and holding work piece to the vice.


Table by left hand = 0.2 min  Time for opening the vice by right hand = 0.2 min

Holding the work piece in the vice with both hands = 0.4 min  

Time taken for lifting and holding file by right hand = 0.2 min  

Time taken for hand filing with both hands = 1.00 min  

Time for bringing the micrometer by right hand = 0.2 min

Time taken in checking dimension with both hands = 0.8 min  

Time for opening the vice by right hand = 0.2 min  

Time taken in removing work piece with left hand = 0.2 min



Micro motion Study
Dept……………………………………………. Film No……………….
Analysis Sheet
Operation: Finish hand fillings
Charted By……………….
Date……………………………………………………………………………….. Operator…………………


Construction of “SIMO” Chart:

The SIMO graph for the assessment sheet of the left and right side informs about the degree of involvement of both sides. Using a SIMO graph, the period for each Therblig reported on the assessment sheet can be displayed to scale. Either the SIMO graph can be separately designed or the graph can be built from the information on the evaluation sheet.

SIMO CHART (Corresponding to Fig. 4.12)




Department: …………………………………. Film No…………………

Operation: Finish hand filling

Charted By……………..
Date………………………………………………………………………………. Operator………………..

A SIMO graph is useful as it enables for very precise and comprehensive evaluation. It is possible to study the working process of the film, readily, comfortably and away from the embarrassing environment of the real work station. In order to grasp a picture of the complete cycle in total detail, the SIMO chart is critically examined and helps to better combine the desired motions.
For improving the methods following procedure is followed:
(i) Workstation locations with non-productive Therbligs such as search, pick place and schedule etc. are re-examined in order to eliminate as far as feasible these fundamental aspects.
(ii) Attention is focused on efficient therbligs such as charged shipping, disassembly, assembly and use, etc., which may be re-sequenced to decrease the overall cycle time and fatigue of the carriers.
(iii) Laws of Motion Economy contribute to the improvement of the current operation method.

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