RWF Messages and News
WFC Times blauw03

Latest version of WFS/RWF software

The latest version of RWF/WFS, released by the WFGD, is version WFS 7.75 of January 2017, inwhich the Export function is extended with the choice between a plain txt-file and a csv-file. In the cvs-file exportation, the 2 formulae for summation are being preserved.
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Addition to
RWF Manual
August 2013
 

After the study of Mental Load, we looked more intensive into the time for Rn and De. From this study new rules were developed.

11.3. ACTING, Rn
With this is understood the time span between the actual seeing (or hearing or feeling) of an action signal and the start of the following action as a reaction on basis of recognized information.

Anticipated or Unanticipated signal.
On a category A signal can be anticipated fully, because the signal is known as well as the time the signal will be noticed.
On a category B signal can be anticipated, because the signal is expected but it is not known which signal or when it is to be noticed exactly.
On a category C signal can not be anticipated, because the signal is not expected and the time it will be noticed is not known.

11.3.1. React (Simple React)
With reacting is understood the undertaking and starting of an action on basis of the recognized information. The time tabel gives for react Rn = ! = 2 RU.
Simple react is the reaction on 1 action signal, as on a light, sound or pressure signal. This will only be valued in time when a reaction on an UNANTICIPATED signal is needed. Reaction on a anticipated signal is not rewarded in time.

Examples of  simple react:
1. A worker operating a machine knows exactly that the machine will stop at the end of the cycle or task and that he
     must pull a handle immediately, if so; cat A. So, no time for react.
2. A worker looks at a little lamp: as soon as it lights up, he must press a knob. Cat B; no time for react.
3. On a wiring machine the horn will sound loudly on the breaking of the wire. This sound is unexpected, cat C. Therefore
   time for react must be given before the next action will take place.

11.3.2. Decide (Choice React)

When a choice must be made out of more than 2 possibilities each with a corresponding action, only then time may be rewarded for reaction time. So, a simple yes/no decision is not rewarded in time, as the time is already compensated for in the inspection time, Ins, itself.
If, after the inspection (Ins), a decision is needed out of 3, 4 or 5 possibilities which can be anticipated upon, so cat. B, than a time of 2 RU is rewarded. For a decision out of 6, 7 or 8 possibilities a time of 2 x Rn = 4 Rn will be rewarded.
If no anticipation is possible, cat. C, for every 2 possibilities a time of 2 RU will be rewarded up to a maximum of 8 possibilities.

Examples of choice react:
1. Playing cards must be sorted into 2 stacks: red and black. No time for decision: choice from 2 possibilities: Fo, Ins.
2. Playing cards must be sorted into 4 stacks: spades, hearts, diamonds and clubs. Choice from 4 possibilities each with
   different action. Time for reaction is rewarded: Fo, Ins, 1 Rn.
 

Mental Load
August 2013

As from RWF/WFS version 7.0 the new ML-module is tested and evaluated. We are almost at the point of a new RWF release, but still want to execute two more tests. See for more information under Mento -Factor News.
We will keep you informed of our progress via WS Tip.
 

Measuring
Mental Load
with RWF
May-June 2013

Because of the finding and study of an old article about Measuring Mental Load or Strain with RWF, we were enthou-siastic and confident to implement the findings in the RWF software. During manual labour signals are send and received by the brain regularly and continously in order to execute all the motions of a task good and adequately. This results in a mental load, especially when (too) high and (too) low mental strain alternate frequently and/or continue for too long.
Mr. Joachim Kurz of the WFGD offered his services and agreed to build this Mental Load Module into the existing RWF software. 
 

WFS New release



Changes to the RWF manual

The WFGD has released a new version of WFS, version WFS 5.91 in April 2007.
In the content nothing has been changed, but following the language module of VWF, the WFGD has decided in close cooperation with the WFR, to add the option “Language”.  From this version on, the user can choose to analyse in a Dutch language environment or a German or an English, inclusive the respective WF ”Rules”.

Improvements to the RWF manual as from January 2007.
Beside some textual improvements, the following modifications and extensions to the RWF manual have been adopted.

The most essential change is the modification regarding the additional T with connected pins and holes. This modification is the result of further consequences of various analyses of connected pins and the discrepances found, ánd the consultation of English and German manuals, ánd the book of Quick, Duncan en Malcolm.
 

 

 

Chapter

Paragr.

Description

0. Introduction
4. Transport



5. Grasp








7. Pre-position



8. Assemble

















10. Process Time
11. Mental
       processes














12. Body
       movements



13. Special
       applications

0.3.1.3b
4.1.3.
4.1.3.3
4.1.3.6
4.2.1
5.1.3.

5.1.5.
5.2.1.
5.2.2.
5.2.4.
5.3.2.

5.3.5.
7.6.



8.1.8.1.






8.1.9.
8.1.10.



8.2.7.





10.2.
11.3.














11.4.
12.

12.6


13.2.



13.5.

A description of the VWF system has been included.
Improvement of the definition of "factor of influence".
Added: Variable resistance and frictionalresistance.
Extension of definition of “Precaution”.
Added: Manner of writing; the other sections will move 1.
(Span with grasp -100 mm; for round objects (pins) height +6 mm; for flat objects, (plates) height +3 mm).
Added: Weight build up and weight run-down
Added: Kantelgreep
Added: Scheidingsgreep
Added: Manipulative grasp: Veelvoudige greep
When the percentages Entangle, Nested or Slippery are (much) larger than 4%, than the necessary actions should be seperately analyzed.
Added: Distance between grasps.
EXTRA FINGER MOVEMENTS. Chapter devided in:
7.6.1. Extra finger movements for bringing outside the fingers of small objects with
         f.i. fine assembly work.
7.6.2. Extra finger movements to bring or get object in or out the palm of the hand.
RULE 8-9: WHEN 2 CONNECTED PINS OR HOLES ARE BEING
               ASSEMBLED, THE ANALYSIS WILL BE AT
                     DB -16 cm: ASSEMBLE with DB + T
                     DB -32 cm: 2 CONSECUTIVE ASSEMBLES *) + T
                     DB +32 cm: 2 CONSECUTIVE ASSEMBLES *) +5 VU + T
                     *) 2 consecutive assembles: the 2nd assemble is a mechanical
                     I-assemble without upright.
Added: Transition from Assemble into Transport
Seat:
Divided into 3 parts: page 369: Seat : Consecutive assembles
                             page 373: Seat: Locking
                             page 377: Seat: Pushing or pressing
Page 425:
With the exception of allowance for permanent blind (PB) the other allowances discussed  ......, etc. add "3. temporarily blind".
NB. Index (T) is always necessary, even if the distance between the 2 points is +16 cm; so even if two consecutive assembles must be analyzed. (Thus: modify the example on page 430).
Functional Times
Page 503:
11.3. ACTING
Acting is the act of taking action on the basis of recognized information.
11.3.1. React.
           Add: "Simple react: reaction to an unespected signal."
11.3.2. Decide.”Choice react”
11.3.3. Memorize and recall.
             a. By MEMORIZE ..........
             b. By RECALL .........
11.3.4. Compute.
           Add: "- Reading a ruler, slide-ruler or scale: 24 RU, 13 RU en 10 RU."
11.3.5. Write.
11.3.6. Count.
           Just by making use of MF-C it is possible to deduct the following formulae
           for counting up to 5 objects: Fo, Ins x n, where n is the number of objects.
Page 521: OVERVIEW
Page 529: Add: "Some weight or hindrance does not or merely influence the time
                         for leg movements.”
Page 543:
Add: "Stairs: hampered up or down, 13 RU per step” (WFGD), and
       "Kneeling: on 1 knee: 18 RU; on 2 knees: 35 RU” (WFGD)
Page 562:
Add: "A spanner or wrench is turned over a partucular distance and is then
         stopped by “collision” against the inside of the fingers. Therefore, the turn,
         without resistance, is a basic movement.”
TABLES FOR REPETITIVE MOTIONS
This section 13.5 is extended with a paragraph on assebles for short cycle repetitive assembly work; as well as for mechanical as for surfave assembly work.
This is no part of the normal examination of RWF analists.

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