MIL-HDBK-683(AT) Statistical Process Control (SPC) Handbook - Implementation & Evaluation PDF (EN)

Downloaded from https://www.everyspec.com I m MRAs~ SENSITIVE I MIHD#3K-683(AT) SUPERSEDING (8BE 9.2) MILITARY HANRBOOK STATISTICAL HWCKSS ~L (SW IHPLEHENTATION AND KVALUATI@ AID AMSC N/A AREA QCIC ~. Approved for public release; distribution is Unllmited.

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Downloaded from https://www.everyspec.com HIL-HDBK-683(AT) FOREWORD 1. This military handbook is approved for use by all Departments and Agencies of tb De~*nt of DefenOe. 2. Beneficial caments (recommendations, additions, deletions) and any pertinent data which may be of use in improvhg this document should be addrea8ed to: U.S. Army Tank-Autmotive ~, ATTN: AM5TA-GDS, Warren, MI 4B~7-5000, by using the self-addrea~ Standardization I~ement Propmal (DD Form 1426) appearing at the end of by letter. !bcument this docment or 3- ~.

mix between For the bodY of technical knowledge involv-~ statistical process mntrnl (S=), we can-look back to the pioneering work done by ktor Shewhart in the days before World War II (wII). During that war, the War Board taught SE techniques as part of its overall Statistical Quality Control (SQC) program. FollowhgPW/11 , certain large manufacturers in the United States (U.S.) installed SPC; but for a number of reasona it wa8 later discarded as not being appropriate for commercial application. The history of technological advancement has been a brea%hrouglw in both the private sector and the military. b.

The military had adopted MIbSTD-105 for attribute sampling, which aemed very well during YWUI, lmt utilized the basic approach of detection rather than prevention. This resulted in batch rejection of material whenever it wa8 found by inspection to be non-confoming to specification, after the fact. The usual scrap, rework and late deliveries were the natural result. c. With inexpensive energy, great ~ for peace in the world and an unlimited market for American products with little competition, quality waa not at the top of the list of priorities. Price and delivery often ranked higher. d.

However, in the arena of higher volume production where quality wan w~ t, the opportunities for the greatest gains offered by SFC first became wident, namely for: - Zero defects quality - kwer Cost - Timely delivery - Better products ii

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Downloaded from https://www.everyspec.com HIL41BK-683(AT) e. In the ~ial arena during * sid-1970-s. the Awri(xsn public really started 8eeing better products, often with a lower price tag; and interestingly G O@ &m a uourus generally identified historically M -* MoA= mxluota, ~ly, tlM Japmeae. BY the mid”1980”8, -ica”a ca6ud awamcnw of tlm Jawmooe iiwa6im with their umerbr quality produots and deeigne had ‘Ohangd to an aouta amarWm88 that * wan surpaadng the U.B. * their iduatr%al superiority. f. I&ring #m MM)%, thin imanion waa not Mmited to Japan. Once other oountria8 beoam swam that Japan-a 8ecmt uumpon =rked and that it waa available to & as well, the flood gates opewd.

Yen, we now have * entire international opeotrum of Japan$ W@ Kong, SingapuMW, Tti- and Korea battling for the world market with the U.S. at the top of their market@g list. I ~- The U.S- industrial superiority that set the world paoe following - HI I hae taken a revere beating. America-s slide baclmnrds does not have to centinue. It does, however, require accurate asaesammt and recognition of how we lost that ground and the need for development of a Bound program to reinstate ~elvea. h. American *try, aa the major eupplier of U.S. military equigmwmt, is being challenged to update ita technical zwmurce 8, knowledge and c~itment.

The mrnera~ for *M would-be auppliem to the nili&y, aa defined in this document, is to recognize that one of the -or requimwn tB for eligibility to participate in the challenge i8 the actual implementation of an WCprogram. The purpose of this handbook ia to serve aa a guide for SPC impl~ntation and program audit. It iO designed for uae by Goverment personnel for reviewing & aaeeaaing a oontractor”a SPC ayatem, set-up, and performance. It may alao be used by 8upplier8 in esta.liahing their WC ayBt4me. b. This handbook alao acts aa a bridge between SPC theory and application and aa a r8ferenoe document to evaluate m pro#mma and tools.

Quality and productivity ~ta start with baaic technical lmowledge, but will mt be fully raa15zed without a e)tmacturedmm for applying the knowledge and auataining the improvements through continuous wnitorlng, feedback, and commitxnentto corzwct problems when identified. Fomulaa and examplea of SFC are available in a wide variety of emllent textbooks. The problea remalna. however, that knowledge of statistical methods alone ia not aufficient to bring &t improvements in quality and productivity. iii

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Downloaded from https://www.everyspec.com MIL-HDBK-6B3(AT) 5. ~. Proper application of statistical theory ia fundmentaltoanysmprogram,but itisnot anoughby it8elf to get youto the required goal. me e8eantial guide for an s= program~ fM managment in the fom of an implementation plan. buntleas organization, perhaps even ymr own, lame learned that cl~ in 8txxti6tioeare mt enough. ~ffeotive oontrol charts won-t mgicdly appear just because the company has aponaored a one day seminar.

To make SK work, a etep-by-utep process, whoee emphasis ie implementation, la required with support, ~ici~tion, and visibility at all levels of managmmt and a folluu-up Syatm must be G tahlidled to en8ure tiDely Complet ion of all critical steps and continued use of WC techniques. For Implementation PUP088Z3, contractor should canaider the follmdng: a- ~. The contractor should provide a practical WC system-8 manual to define and support their efforts. This manual should specify th following: (1) Their philos+y, including their quality comdtment. (2) Their policy statements designed to implement their company philosophy.

(3) Their standaml operating procedure (SOP) dmigned to eupport the stated ~liciee. The SOP in ~ticular ehould define the implmentat ion elements of WC. b. ~ . In-plant applications for SPC should be utilized by contractors, as follows: (1) At receiving inepction if your supplier is not using SW control ae required by this guide. Since this ia detection, after-the-fact and contrary to the intent of this guide, this will be considered a temporary condition and will be governed by the tams of your individual ~ orders. Any approvale for contracte would be conditional and teqporary.

The lifting of such conditional approvals would b directly related to the supplier“a having upgraded their in-process syatema to fully utilize SE. \ (2) Ihring manufacturing where the application of appropriate charts is mandatory. Zhia ia subject to surwy and audit prior to pumhase order releaae and on-going audit suxmmillanoe, thereafter, on both the =* and mibcontractora. (3) At final inspection and audit. 6. Mdb&hgy.

The prime contractor”8 SOP for mbcontmctor surveillance and control should &fine methodology for auditing, evaluating and controlling each supplier (subcontractor) in term of both required SPC and other SOP and policy statement areas in which the supplier i8 required to provide adequate coverage. iv

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