International D ISO Standard IS07870-6 Second edition Control charts - 2024-07 Part 6: EWMA control charts for the process mean Cartes de controle- Partie6:CartesdecontroleEWMA pour lamoyenne d'un processus Referencenumber IS07870-6:2024(en) ISO2024 IS07870-6:2024(en) COPYRIGHTPROTECTED DOCUMENT @IS02024 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either Iso at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch.de Blandonnet 8 CH-1214 Vernier, Geneva Phone:+41227490111 Email:copyright@iso.org Website: www.iso.org Published in Switzerland IS0 2024-All rights reserved ii IS07870-6:2024(en) Contents Page Foreword. .iv Introduction V 1 Scope. .1 2 Normative references .1 3 Terms and definitions .1 4 Symbols and abbreviated terms. .2 5 EWMAfor inspectionbyvariables 3 5.1 General 3 5.2 Weighted averageexplained 3 5.3 ControllimitsforEWMAcontrolchart 4 5.4 Construction ofEWMAcontrolchart .5 5.5 Example .7 6 Choiceofthe control chart 10 6.1 Shewhart control chartversusEWMA control chart .10 6.2 .11 Average run length. 6.3 ChoiceofparametersforEWMAcontrolchart 11 6.3.1 Choice of 入 .11 6.3.2 Choice of Lz 12 6.3.3 Calculation for n 12 6.3.4 Example 13 7 ProcedureforimplementingtheEWMAcontrolchart .13 8 SensitivityoftheEWMAtonon-normality .14 9 Advantages and limitations 14 9.1 Advantages. .14 9.2 Limitations .14 Annex A (informative) Application of the EwMA control chart .16 Annex B (informative) EwMA control chart for aproportion of nonconforming items. .20 AnnexC (informative)EwMAcontrol chartsfora numberofnonconformities .22 Bibliography .24 IS0 2024-All rights reserved iii