En la oficina de patentes

A   definitive   improvement   potential   is   found   regarding   the   ratio   of   corrective   maintenance  and  PM.  Out  of  all  the  76  companies  in  this  survey,  two  thirds  indicated  to   have  less  than  50  percent  PM,  and  merely  21  stated  to  have  more  than  50  percent  PM.   However,   continuous   production   companies   were   shown   to   in   general   have   slightly   larger  amount  of  PM,  but  the  fact  remains  that  the  majority  of  all  maintenance  activities   are   carried   out   as   corrective   maintenance.   In   contexts   of   purely   random   breakdowns  

and   low   maintenance   costs,   corrective   maintenance   might   be   the   most   appropriate   strategy   (Jonsson,   1999a).   However,   as   the   results   in   this   survey   also   show   that   most   respondents  are  experiencing  re-­‐occurring  chronic  PD  and  report  high  estimated  cost  of   stoppages,  most  companies  seem  to  have  a  production  environment  that  does  not  call   for   high   amounts   of   corrective   maintenance.   But   even   more   important   is   the   fact   that   corrective  maintenance  does  not  only  result  in  higher  maintenance  costs  and  decreased   availability  (Mobley,  2004)  but  it  is  also  a  severe  safety  issue  as  it  is  the  situation  where   most   accidents   occur   to   maintenance   operators   (EU-­‐OSHA,   2010).   The   results   in   this   survey   thus   indicate   that   a   shift   towards   increased   PM   and   reduced   corrective   maintenance   is   an   urgent   issue   that   needs   to   be   addressed   in   order   to   achieve   more   effective,  efficient  and  safer  maintenance  in  Swedish  industry.  

It   is   not   easy   to   transform   ones   entire   approach   to   maintenance   operations   without   clear   principles,   guidelines   and   implementing   instructions.   This   is   where   the   maintenance  concepts  like  TPM  and  RCM  comes  to  play.  The  results  do  however  indicate   that   few   companies   are   to   a   high   degree   following   the   principles   and   work   practices   preached   in   these   concepts.   In   detail,   30   companies   work   with   TPM   to   a   high   or   very   high  degree,  and  merely  19  with  RCM.  Moreover,  32  companies  state  to  be  employing   work   practices   and   techniques   according   to   the   CBM   approach.   A   large   improvement   potential   in   increasing   the   popularisation   these   maintenance   concepts   in   Swedish   industry  can  thus  be  identified.  This  yet  again  calls  for  closer  collaboration  between  the   industry  and  the  academic  world  since  the  high  level  of  education  and  knowledge  of  the   concepts   can   be   found   in   academia,   whilst   the   value   of   putting   them   to   practice   is   naturally  at  the  shop  floors  in  companies.    

The  data  also  shows  that  larger  companies  are  to  a  much  greater  extent  working  with   these   concepts.   This   is   likely   an   effect   of   both   having   a   much   more   defined   and   developed  maintenance  department,  but  also  more  available  resources  for  investing  in   the   development   of   maintenance   operations.   On   the   other   hand,   one   can   argue   that   characteristics   such   as   the   closer   communication   and   a   flatter   organization   found   in   smaller   companies   can   enhance   the   possibility   to   achieve   high   involvement   and   company-­‐wide  integration  of  maintenance.  In  addition,  a  transformation  towards  TPM   can  also  be  achieved  with  little  resources  as  many  of  the  principles  is  based  on  simple   and   cheap   solutions   such   as   operator   maintenance   and   continuous   improvements   through  small  team  activities  (Nakajima,  1998).  Nevertheless,  a  necessity  for  long-­‐term   success  with  any  maintenance  concept,  regardless  of  company  size,  is  yet  again  the  full   support   from   top   management   and   the   stipulation   of   a   clear   maintenance   strategy   (Nakajima,  1998;  Ylipää,  2000).    

A   deeper   look   into   the   application   of   work   practices   emphasised   in   the   various   maintenance   concepts   indicated   a   large   improvement   potential   in   utilizing   the   fundamental   TPM   feature   of   autonomous   operator   maintenance.   In   detail,   22   respondents  indicated  that  operator  maintenance  is  utilized  to  a  relatively  high  degree   in  their  company,  and  9  stated  it  to  a  very  high  degree.  There  are  likely  many  and  varied   social   aspects   to   overcome   in   order   to   develop   more   flexible   shop   floor   employees   where  the  work  content  includes  both  production  and  maintenance  tasks.  A  reason  for   the  opposition  amongst  production  operators  to  carry  out  maintenance  could  be  due  to   the   long   tradition   of   viewing   operators   to   be   responsible   for   running   the   system,   and   maintenance  to  be  responsible  for  keeping  up  the  availability  of  the  machinery  (Ylipää,  

2000).   This   unfortunately   also   prevents   companies   to   utilize   cheap   and   simple   predictive   techniques   such   as   visual   inspection   or   oil   sample   testing   carried   out   by   operators  (Alsyouf,  2007).  Instead  the  results  in  this  survey  show  that  many  companies   hire  external  personnel  to  carry  out  maintenance,  indicated  to  a  relatively  high  or  very   high  degree  by  41  out  of  76  respondents.  Especially  continuous  production  companies   are  found  to  utilize  external  personnel,  but  this  is  likely  an  effect  of  that  major  overhaul   and   maintenance   of   advanced   equipment   found   in   these   industries   often   require   specially  trained  repairers.  Nevertheless,  one  cannot  deny  the  unexploited  potential  of   more  in-­‐house  autonomous  operator  maintenance.    

The   results   in   this   survey   did   however  imply   that   production   operators   are   to   a   large   extent  involved  in  improvement  teams,  indicated  to  a  relatively  high  or  very  high  degree   by   57   out   of   76   respondents.   However,   having   maintenance   personnel   involved   in   improvement   teams   is   slightly   less   common,   and   it   is   rare   that   production   and   maintenance   operators   collaborate   to   plan   and   carry   out   maintenance.   These   findings   combined   with   the   results   that   indicated   low   satisfaction   with   how   the   teams   are   working,   signals   a   definitive   improvement   potential   for   small-­‐group   continuous   improvement   activities   in   a   maintenance   context   in   Swedish   industry.   Not   only   can   cross-­‐trained   teams   with   maintenance   representatives   reduce   PD,   improve   overall   production  performance  and  achieve  much  more  efficient  maintenance  (Jonsson,  1999a;   Smith  &  Hawkins,  2004),  but  striving  for  cross-­‐training  of  maintenance  and  production   operators  and  applying  a  team-­‐based  approach  to  maintenance  can  also  build  a  base  for   a  learning  organization  (Smith  &  Hawkins,  2004).    

These   findings   also   impose   a   dilemma   for   the   gap   between   the   situation   in   top   management  and  what  actually  happens  on  the  shop  floor.  As  discussed,  the  results  in   this  survey  show  that  most  respondents  (who  are  primarily  representing  an  expert  view   from   a   high   management   level)   consider   maintenance   to   be   synchronized   with   production,   but   there   are   fairly   low   level   of   collaboration   between   maintenance   and   production   on   the   shop   floor.   This   situation   call   for   more   holistic   approaches   to   measurements  of  maintenance  performance  that  can  concretize  top  level  maintenance   objectives  to  an  operative  level  and  make  maintenance  more  prioritized  throughout  the   entire  organization  (Van  Hoorenbeek  &  Pintelton,  2014).    

Looking  closer  into  work  methods  and  techniques  found  in  RCM  and  CBM,  the  results   indicate  that  bottleneck  analysis,  CM  and  criticality  assessment  is  employed  to  a  fairly   low  degree.  CM  is  stated  to  be  used  to  a  relatively  high  or  very  degree  by  31  out  of  76   respondents   and   also   found   to   be   more   common   in   both   larger   and   continuous   production  companies.  A  reason  for  this  could  be  that  CM  is  assumed  to  only  consist  of   techniques   such   as   vibration   or   thermography   analysis   that   require   expensive   and   advanced   equipment   to   be   effective.   However,   as   pointed   out   by   Alsyouf   (2007)   and   Idhammar  (1992),  one  of  the  most  profitable  applications  of  CM  techniques  is  to  utilize   cheap  and  simple  methods  such  as  visual  inspection,  oil  samples  or  to  have  operator  use   their   human   senses   to   monitor   equipment   and   prevent   problems   by   lubrication   or   routine  cleaning.    

To   find   bottlenecks   in   production   means   to   find   the   equipment   that   strangles   the   production  rate  and  limits  capacity.  Proper  maintenance  of  the  bottlenecks  is  of  extreme   importance  since  disturbances  on  this  equipment  will  affect  the  entire  production  flow.  

In  this  survey,  43  out  of  76  respondents  indicated  that  bottleneck  analysis  is  performed   to   a   relatively   high   or   very   high   degree   at   their   company.   A   way   of   utilizing   the   bottleneck   analysis   to   ensure   adequate   maintenance   is   to   incorporate   it   with   the   establishment   of   criticality   assessment   of   equipment.   Criticality   assessment   quantifies   how  important  an  item  or  system  function  is  in  relation  to  production,  and  the  purpose   of  establishing  the  criticality  levels  is  to  schedule  maintenance  based  on  the  equipment   with  the  highest  criticality   (Smith  &  Hawkins,  2004).  In  this  survey,  only  27  out  of  76   respondents   indicated   that   their   company   established   criticality   levels   to   a   relatively   high  or  very  high  degree.  An  effect  of  not  knowing  the  criticality  of  the  equipment  is  that   the  preservation  of  the  intended  function  in  not  put  in  focus  and  all  functional  failures  are   treated  equally  from  a  maintenance  perspective  (Hinchcliff  &  Smith,  2003).    

Moreover,   the   results   in   this   survey   also   show   that   criticality   levels   of   equipment   are   seldom   updated.   An   issue   with   this   is   that   in   today’s   manufacturing   environment   characterized   by   both   tightly   coupled   flows   and   frequent   changes,   it   is   not   only   the   production  itself  that  is  dynamic,  but  also  the  critically  of  the  equipment.  For  example,  as   bottlenecks  are  resolved  and  capacity  is  freed  up,  another  part  of  the  production  process   becomes   the   bottleneck.   This   means   that   the   equipment   that   is   most   critical   from   a   maintenance   perspective   has   changed,   showcasing   the   fact   that   that   criticality   assessment  of  equipment  can  easily  present  a  deceiving  view  unless  a  dynamic  approach   to   updating   them   is   also   employed.   This   survey   also   covered   on   what   basis   criticality   levels   are   established,   and   the   results   indicated   that   ABC-­‐classification   is   the   most   commonly   applied   method,   indicating   an   improvement   potential   for   developing   and   popularizing  more  dynamic  approaches  to  criticality  assessment.