FTAとは?

医薬品業界や医療機器業界では、リスクマネジメントにおいて各種のリスクマネジメント手法を持ちいる。
リスクマネジメント手法は著名なものだけでも以下のようなものがある。

  • 欠陥モード影響解析(FMEA
  • 欠陥モード影響致命度解析(FMECA)
  • 故障の木解析(FTA)
  • ハザード分析と重要管理点(HACCP)
  • 潜在危険及び作動性の調査(HAZOP)
  • 予備危険源分析(PHA)
  • リスクランキングとフィルタリング
  • 支援統計手法

製造設備のリスクマネジメントにおいては、欠陥モード影響解析(FMEA)が多く用いられる。
一方で、故障の木解析(FTA)は意外とその利用方法が理解されていないことが多い。

FMEAは、「もしこのような故障が発生したら、その結果どのような影響を受けるか」というような質問を体系的に設定する帰納的な手法である。つまりボトムアップ的な手法である。
それに対してFTAは、FMEAとは対称的に、想定した「好ましくない結果」 (危害発生の事故等)から出発する演繹的な方法である。
つまりトップダウン的な手法である。
FTAは、その事象(事故等)をもたらす可能性のある原因や事象を、それ以上分解できない基本事象まで遡って分析する原因解析型手法である。
論理記号(AND、OR等)を用いて図式化することで、複雑な因果関係を把握できるため、想定しにくい事故原因・ハザードの網羅的・早期対策(FMEAの確認・水平展開)や、特定の事故の再発防止対策を講じるための分析手法として有効である。

今、ガスが爆発したという事象(事故)について、FTAを使用して原因分析を試みてみよう。(下図参照)

まずガスが爆発するためには、「点火源」と「空気」と「可燃性ガス」が同時に存在しなければならない。
ここで空気をなくすことはできないので「空気」は除外する。
「可燃性ガス」が存在するということは、タンクから漏えいしたこと以外に考えられない。
図においてこの「タンクからの漏えい」はもうこれ以上原因を展開するできないため非展開事象と呼ぶ。
非展開事象はひし形で表す。
次に「点火源」であるが、「熱源」か「電気火花」か「直火」が原因であると考えられる。
「熱源」と「直火」は非展開事象である。
「電気火花」の原因は「断線」または「ショート」である。
「断線」や「ショート」も非展開事象である。

お分かりであろうか。
ガス爆発の再発を防ぐためには、「熱源」や「直火」を遠ざけ、「断線」や「ショート」や「タンクからの漏えい」を防止すれば良いのである。

FTAはこのように事故の原因を究明するのに有効である。
FMEAとFTAを組合せたならば、より確実なリスク分析が実施できる。

一般にFTAは、事故が発生し、その再発防止の目的でCAPAを実行する際などに使用する。
CAPAにおいては「なぜなぜ分析」(5Whys)を実施することがあるが、FTAはそれを上記のように論理記号等を用いてロジカルに根本的原因を究明する。
医療機器の設計変更時などに有効である。


Related post

Comment

  1. edppaqjuf phths dwnturr xbbt sksoqovossmnocy

  2. I was more than happy to uncover this great site. I want
    to to thank you for your time just for this fantastic read!!
    I definitely loved every part of it and i also have you saved
    as a favorite to see new stuff on your website.

  3. What’s up to every single one, it’s genuinely a pleasant for me to pay a quick visit this web page,
    it contains important Information.

  4. Saved as a favorite, I really like your blog!

  5. Everything is very open with a clear clarification of the challenges.
    It was definitely informative. Your site is very useful.
    Thanks for sharing!

  6. Thank you for another informative site. Where else may I get that type of
    info written in such a perfect method? I’ve a mission that I’m simply now
    operating on, and I’ve been on the look out for such info.

  7. Attractive part of content. I just stumbled upon your blog and in accession capital
    to say that I get in fact enjoyed account your blog posts.
    Anyway I’ll be subscribing to your augment or even I
    fulfillment you get entry to persistently rapidly.

  8. Thanks for the marvelous posting! I quite enjoyed reading it, you may
    be a great author. I will be sure to bookmark
    your blog and will eventually come back very soon. I want to encourage you to
    definitely continue your great writing, have
    a nice afternoon!

  9. I am always thought about this, thanks for putting up.

  10. Hi there, just became alert to your blog through
    Google, and found that it’s really informative.
    I’m gonna watch out for brussels. I will appreciate if you continue this in future.
    Numerous people will be benefited from your writing.
    Cheers!

  11. I just couldn’t depart your web site before suggesting that I extremely enjoyed the standard
    information an individual supply to your guests? Is going to be back often to check up on new posts

  12. Touche. Great arguments. Keep up the great work.

  13. Wow, this paragraph is good, my sister is analyzing such things, thus I am going to inform her.

  14. Usually I do not learn article on blogs, but I would like to
    say that this write-up very forced me to try and do it!
    Your writing style has been surprised me. Thank you, very
    great article.

  15. I do not even understand how I stopped up here, but I thought
    this publish was once great. I do not understand who you might
    be however definitely you are going to a well-known blogger if you happen to are not already.
    Cheers!

  16. Greetings! Very useful advice within this article! It is the little
    changes which will make the largest changes. Many thanks for sharing!

  17. We’re a bunch of volunteers and opening a brand new scheme in our community.
    Your web site provided us with valuable information to work on. You’ve
    performed an impressive process and our whole community shall be grateful to you.

  18. I am curious to find out what blog system you have
    been working with? I’m having some small security problems with my
    latest website and I would like to find something more safeguarded.
    Do you have any recommendations?

  19. Nice blog here! Also your site loads up very fast!
    What web host are you using? Can I get your affiliate link to
    your host? I wish my website loaded up as quickly
    as yours lol

  20. Attractive component of content. I simply stumbled upon your site and in accession capital
    to say that I acquire in fact loved account your blog posts.
    Any way I’ll be subscribing to your feeds and even I success you access persistently rapidly.

  21. I was wondering if you ever thought of changing the layout of your site?
    Its very well written; I love what youve got to say.
    But maybe you could a little more in the way of content so people could connect with it better.
    Youve got an awful lot of text for only having 1 or 2 images.
    Maybe you could space it out better?

  22. Hi! I’ve been reading your weblog for a long
    time now and finally got the bravery to go ahead and
    give you a shout out from Dallas Tx! Just wanted to mention keep up the great job!

  23. Great beat ! I wish to apprentice while you amend
    your site, how can i subscribe for a blog site? The account aided me a acceptable deal.
    I had been a little bit acquainted of this your
    broadcast provided bright clear idea

  24. I know this if off topic but I’m looking into starting my own weblog and was curious what all is
    needed to get setup? I’m assuming having a blog like yours would cost a pretty penny?

    I’m not very web savvy so I’m not 100% certain. Any tips or advice would be greatly
    appreciated. Thank you

  25. Article writing is also a excitement, if you know
    afterward you can write if not it is complicated to write.

  26. Please let me know if you’re looking for a article author for
    your blog. You have some really great articles and I believe I
    would be a good asset. If you ever want to take some of the load off, I’d really like to write some
    material for your blog in exchange for a link back to
    mine. Please shoot me an e-mail if interested. Regards!

  27. What’s up Dear, are you actually visiting this website daily, if so then you will definitely obtain fastidious knowledge.

  28. Your means of telling the whole thing in this article
    is in fact nice, every one be capable of easily know it, Thanks a lot.

  29. Incredible! This blog looks exactly like my old one! It’s on a totally different topic but it has pretty much the same page layout and design. Superb choice of colors!

  30. We stumbled over here by a different page and thought I might as well check things out.
    I like what I see so i am just following you. Look forward to looking into your web page
    again.

  31. Hey just wanted to give you a brief heads up and let you know
    a few of the pictures aren’t loading correctly.
    I’m not sure why but I think its a linking issue. I’ve tried
    it in two different web browsers and both show the same
    outcome.

  32. Heya i am for the first time here. I found this board and I find It truly useful & it helped me out a
    lot. I hope to give something back and help others like you aided me.

  33. Normally I do not read article on blogs, however I would
    like to say that this write-up very pressured me to
    take a look at and do so! Your writing style has been surprised me.
    Thanks, very nice post.

  34. Hello just wanted to give you a quick heads up. The text in your content seem to be running off the screen in Opera.
    I’m not sure if this is a formatting issue or something to do with internet browser compatibility but I thought
    I’d post to let you know. The layout look great though! Hope you get
    the issue solved soon. Thanks

  35. Hurrah! At last I got a blog from where I be
    capable of truly take helpful information concerning my study and knowledge.

  36. I am really inspired along with your writing talents as well as
    with the structure to your weblog. Is this a paid subject or did you modify it yourself?
    Either way stay up the nice high quality writing, it’s uncommon to look a nice weblog like this one today..

  37. Hello, Neat post. There is an issue along with your site in internet explorer, could
    test this? IE nonetheless is the marketplace chief and a good component of people will
    pass over your magnificent writing due to this problem.

  38. Ahaa, its pleasant dialogue about this paragraph at this place at this website, I have read
    all that, so at this time me also commenting at this place.

  39. Hi excellent blog! Does running a blog like this require a large amount of
    work? I’ve virtually no understanding of computer programming but I was hoping to start
    my own blog soon. Anyway, should you have any suggestions or
    techniques for new blog owners please share.
    I know this is off subject but I just had to ask.
    Thanks a lot!

  40. Thanks for another informative web site. Where else may just I get that kind
    of info written in such an ideal way? I’ve a project that
    I’m simply now working on, and I have been at the look out for
    such information.

  41. It’s appropriate time to make some plans for the longer term and it is time to be happy.
    I have learn this publish and if I may just I want to recommend you some interesting things or suggestions.
    Maybe you can write next articles regarding this article.
    I wish to read even more things about it!

  42. Woah! I’m really enjoying the template/theme of this
    blog. It’s simple, yet effective. A lot of times it’s challenging to get
    that “perfect balance” between user friendliness and visual
    appeal. I must say you’ve done a excellent job with this.
    Additionally, the blog loads very fast for me on Internet explorer.
    Outstanding Blog!

  43. I simply could not go away your website before suggesting that I really enjoyed the standard information an individual provide for your guests?
    Is gonna be again continuously to investigate cross-check new posts

  44. I loved as much as you will receive carried out right here.
    The sketch is attractive, your authored subject matter stylish.

    nonetheless, you command get got an edginess over that you
    wish be delivering the following. unwell unquestionably come more formerly again since exactly the same nearly a lot often inside case you shield this
    increase.

  45. Your style is unique compared to other folks I’ve read
    stuff from. I appreciate you for posting when you
    have the opportunity, Guess I will just bookmark this page.

  46. you’re actually a excellent webmaster. The website loading pace is amazing.

    It kind of feels that you are doing any distinctive trick.
    Furthermore, The contents are masterwork. you’ve done a fantastic job on this topic!

  47. It’s a shame you don’t have a donate button! I’d certainly donate to this brilliant blog!
    I suppose for now i’ll settle for book-marking and adding your RSS feed to
    my Google account. I look forward to new updates and will talk about this site with my
    Facebook group. Talk soon!

  48. I was pretty pleased to find this page. I want to to thank you
    for your time just for this fantastic read!! I definitely appreciated every part of it and
    I have you book-marked to look at new information in your site.

  49. Hmm is anyone else having problems with the
    images on this blog loading? I’m trying to find out if its a problem on my
    end or if it’s the blog. Any responses would be greatly appreciated.

  50. Quality posts is the key to interest the people to visit the website, that’s what this site is providing.

    • Online cricket id
    • 2024.02.28

    It’s very trouble-free to find out any topic on net as compared to books,
    as I found this piece of writing at this site.

  51. Have you ever considered publishing an e-book or guest authoring on other websites? I have a blog based on the same information you discuss and would really like to have you share some stories/information. I know my subscribers would enjoy your work. If you are even remotely interested, feel free to shoot me an e-mail.

  52. certainly like your web-site but you need to check the spelling on quite a few of your posts. Many of them are rife with spelling problems and I find it very bothersome to tell the truth nevertheless I will certainly come back again.

  53. I would like to thnkx for the efforts you have put in writing this blog. I am hoping the same high-grade blog post from you in the upcoming as well. In fact your creative writing abilities has inspired me to get my own blog now. Really the blogging is spreading its wings quickly. Your write up is a good example of it.

  54. Very interesting topic, thanks for putting up. “Education a debt due from present to future generations.” by George Peabody.

  55. It is really a nice and useful piece of info. I¦m satisfied that you shared this helpful info with us. Please keep us up to date like this. Thanks for sharing.

  56. Outstanding post, I think blog owners should larn a lot from this blog its very user friendly.

  57. Magnificent site. A lot of useful info here. I’m sending it to a few pals ans also sharing in delicious. And of course, thanks on your sweat!

  58. I truly appreciate this post. I’ve been looking all over for this! Thank goodness I found it on Bing. You have made my day! Thanks again

  59. Hello there, I found your blog via Google while searching for a related topic, your website came up, it looks great. I have bookmarked it in my google bookmarks.

  60. Hey, you used to write great, but the last several posts have been kinda boring… I miss your super writings. Past few posts are just a little bit out of track! come on!

  61. Ikaria Lean Belly Juice is a fast-acting weight loss supplement that is developed to incinerate stubborn fat.

  62. Hello! I just would like to give a huge thumbs up for the great info you have here on this post. I will be coming back to your blog for more soon.

  63. I have been surfing on-line more than 3 hours these days, yet I by no means discovered any interesting article like yours. It’s beautiful value enough for me. Personally, if all web owners and bloggers made good content material as you probably did, the web shall be much more useful than ever before. “Now I see the secret of the making of the best persons.” by Walt Whitman.

  64. Java Burn: What is it? Java Burn is marketed as a natural weight loss product that can increase the speed and efficiency of a person’s natural metabolism, thereby supporting their weight loss efforts

  65. With every little thing which appears to be building throughout this specific area, a significant percentage of viewpoints are fairly stimulating. However, I appologize, because I can not give credence to your entire idea, all be it radical none the less. It looks to us that your comments are generally not totally validated and in reality you are generally yourself not entirely confident of your argument. In any event I did take pleasure in examining it.

  66. My brother suggested I would possibly like this blog. He used to be entirely right. This post truly made my day. You cann’t imagine just how a lot time I had spent for this information! Thank you!

  67. Youre so cool! I dont suppose Ive learn something like this before. So nice to search out any person with some authentic thoughts on this subject. realy thanks for beginning this up. this website is one thing that’s wanted on the internet, somebody with slightly originality. helpful job for bringing something new to the internet!

  68. I’m extremely inspired together with your writing talents as neatly as with the layout to your weblog. Is this a paid topic or did you customize it yourself? Anyway stay up the excellent quality writing, it’s rare to look a nice blog like this one nowadays..

  69. Hi , I do believe this is an excellent blog. I stumbled upon it on Yahoo , i will come back once again. Money and freedom is the best way to change, may you be rich and help other people.

  70. I don’t even know how I ended up here, but I thought this post was good. I don’t know who you are but certainly you are going to a famous blogger if you aren’t already 😉 Cheers!

  71. Dead composed subject material, Really enjoyed reading.

  72. Very well written article. It will be beneficial to everyone who usess it, as well as yours truly :). Keep up the good work – for sure i will check out more posts.

  73. Does your site have a contact page? I’m having a tough time locating it but, I’d like to shoot you an e-mail. I’ve got some suggestions for your blog you might be interested in hearing. Either way, great website and I look forward to seeing it improve over time.

  74. I am very happy to read this. This is the type of manual that needs to be given and not the accidental misinformation that’s at the other blogs. Appreciate your sharing this best doc.

  75. What is Gluco Freedom? Millions of people suffer from blood sugar problems, despite the fact that many factors are beyond their control.

  76. About GlucoTrust. GlucoTrust is a natural supplement that promotes normal blood sugar levels.

  77. Appreciate it for helping out, fantastic info .

  78. But a smiling visitant here to share the love (:, btw outstanding layout. “Everything should be made as simple as possible, but not one bit simpler.” by Albert Einstein.

  79. I like the efforts you have put in this, thank you for all the great articles.

  80. Heya i am for the first time here. I found this board and
    I find It really useful & it helped me out a lot. I hope to
    give something back and help others like you helped me.

  81. It’s hard to search out educated folks on this subject, however you sound like you know what you’re speaking about! Thanks

  82. There is noticeably a bundle to know about this. I assume you made some good points in features also.

  83. Aw, this was a very nice post. In concept I would like to put in writing like this additionally – taking time and precise effort to make an excellent article… but what can I say… I procrastinate alot and certainly not appear to get one thing done.

  84. Hi my friend! I want to say that this post is awesome, nice written and include approximately all significant infos. I’d like to see more posts like this.

  85. Have you ever thought about adding a little bit more than just your articles? I mean, what you say is valuable and everything. However think of if you added some great visuals or videos to give your posts more, “pop”! Your content is excellent but with images and videos, this website could certainly be one of the very best in its niche. Very good blog!

  86. I feel this is among the so much vital info for me. And i’m satisfied studying your article. However wanna remark on few general issues, The web site taste is wonderful, the articles is in reality excellent : D. Excellent task, cheers

  87. Thanks for every other excellent article. The place else could anybody get that kind of information in such a perfect approach of writing? I’ve a presentation subsequent week, and I’m at the look for such information.

  88. WONDERFUL Post.thanks for share..extra wait .. …

  89. I consider something truly special in this website .

  90. Some truly interesting details you have written.Helped me a lot, just what I was looking for : D.

  91. certainly like your website but you have to test the spelling on quite a few of your posts. A number of them are rife with spelling problems and I find it very bothersome to tell the truth on the other hand I will surely come back again.

  92. I?¦ll immediately grab your rss feed as I can’t find your e-mail subscription link or newsletter service. Do you’ve any? Please let me realize so that I could subscribe. Thanks.

  93. I know this if off topic but I’m looking into starting my own blog and was curious what all is required to get set up? I’m assuming having a blog like yours would cost a pretty penny? I’m not very web smart so I’m not 100 sure. Any recommendations or advice would be greatly appreciated. Thank you

  94. What is CogniCare Pro? CogniCare Pro is 100 natural and safe to take a cognitive support supplement that helps boost your memory power. This supplement works greatly for anyone of any age and without side effects

  95. Very nice post. I just stumbled upon your blog and wanted to say that I’ve really enjoyed browsing your blog posts. After all I will be subscribing to your feed and I hope you write again very soon!

  96. Woah! I’m really enjoying the template/theme of this site. It’s simple, yet effective. A lot of times it’s very hard to get that “perfect balance” between superb usability and appearance. I must say you have done a superb job with this. In addition, the blog loads super quick for me on Opera. Superb Blog!

  97. Saved as a favorite, I really like your blog!

  98. I¦ve been exploring for a little for any high quality articles or blog posts on this kind of space . Exploring in Yahoo I ultimately stumbled upon this site. Reading this info So i¦m happy to exhibit that I’ve a very just right uncanny feeling I found out exactly what I needed. I such a lot undoubtedly will make sure to don¦t put out of your mind this web site and provides it a look on a constant basis.

  99. I got what you mean ,saved to my bookmarks, very nice web site.

  100. Well I really liked studying it. This article offered by you is very constructive for good planning.

  101. This really answered my problem, thank you!

  102. of course like your website but you have to test the spelling on several of your posts. Many of them are rife with spelling problems and I in finding it very bothersome to inform the reality on the other hand I will surely come again again.

  103. Lovely just what I was searching for.Thanks to the author for taking his clock time on this one.

  104. Just what I was searching for, appreciate it for posting.

  105. I loved as much as you’ll receive carried out right here. The sketch is tasteful, your authored material stylish. nonetheless, you command get bought an nervousness over that you wish be delivering the following. unwell unquestionably come further formerly again as exactly the same nearly very often inside case you shield this hike.

  106. Hiya, I’m really glad I have found this info. Nowadays bloggers publish only about gossips and web and this is actually annoying. A good website with interesting content, that’s what I need. Thanks for keeping this web site, I’ll be visiting it. Do you do newsletters? Can not find it.

  107. Hey There. I discovered your blog the use of msn. This is a very neatly written article. I will make sure to bookmark it and come back to read more of your helpful information. Thank you for the post. I will definitely return.

  108. I was just searching for this information for a while. After 6 hours of continuous Googleing, at last I got it in your site. I wonder what is the lack of Google strategy that don’t rank this kind of informative sites in top of the list. Generally the top sites are full of garbage.

  109. I’m still learning from you, as I’m trying to achieve my goals. I definitely liked reading all that is written on your website.Keep the posts coming. I loved it!

  110. I like this post, enjoyed this one appreciate it for putting up.

  111. Hey There. I found your weblog the use of msn. That is a really smartly written article. I will be sure to bookmark it and return to learn extra of your helpful info. Thanks for the post. I’ll certainly comeback.

  112. Thanks for this post, I am a big big fan of this web site would like to go on updated.

  113. As you browse through the online flash games, you will be thrilled to see plenty of options right in front of you.

    The more lines selected, the higher the chance of winning but also increases
    the overall cost per spin.

    • Robin
    • 2024.10.19

    That’s why it’s all the more important to us that you are well informed! But Cam2Cam is not everything and you should also take a closer look at the other free adult webcams. For example, you can record the camsex shows with the sexcam recorder and even control a dildo live in the chat with the cam girl!

TOP