{"id":"https://openalex.org/W2109864780","doi":"https://doi.org/10.1145/2027216.2027218","title":"Hardness of Approximating Flow and Job Shop Scheduling Problems","display_name":"Hardness of Approximating Flow and Job Shop Scheduling Problems","publication_year":2011,"publication_date":"2011-10-01","ids":{"openalex":"https://openalex.org/W2109864780","doi":"https://doi.org/10.1145/2027216.2027218","mag":"2109864780"},"language":"en","primary_location":{"id":"doi:10.1145/2027216.2027218","is_oa":false,"landing_page_url":"https://doi.org/10.1145/2027216.2027218","pdf_url":null,"source":{"id":"https://openalex.org/S118992489","display_name":"Journal of the ACM","issn_l":"0004-5411","issn":["0004-5411","1557-735X"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319798","host_organization_name":"Association for Computing Machinery","host_organization_lineage":["https://openalex.org/P4310319798"],"host_organization_lineage_names":["Association for Computing Machinery"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of the ACM","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"http://infoscience.epfl.ch/record/170685","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5053978143","display_name":"Monaldo Mastrolilli","orcid":"https://orcid.org/0000-0002-2948-9749"},"institutions":[{"id":"https://openalex.org/I2614128279","display_name":"Dalle Molle Institute for Artificial Intelligence Research","ror":"https://ror.org/013355g38","country_code":"CH","type":"facility","lineage":["https://openalex.org/I15196421","https://openalex.org/I2614128279","https://openalex.org/I57201433"]}],"countries":["CH"],"is_corresponding":false,"raw_author_name":"Monaldo Mastrolilli","raw_affiliation_strings":["IDSIA, Lugano, Switzerland"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"IDSIA, Lugano, Switzerland","institution_ids":["https://openalex.org/I2614128279"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5046999727","display_name":"Ola Svensson","orcid":"https://orcid.org/0000-0003-2997-1372"},"institutions":[{"id":"https://openalex.org/I174424907","display_name":"Laboratoire d'Informatique Fondamentale de Lille","ror":"https://ror.org/05rhg0h08","country_code":"FR","type":"facility","lineage":["https://openalex.org/I174424907"]},{"id":"https://openalex.org/I5124864","display_name":"\u00c9cole Polytechnique F\u00e9d\u00e9rale de Lausanne","ror":"https://ror.org/02s376052","country_code":"CH","type":"education","lineage":["https://openalex.org/I2799323385","https://openalex.org/I5124864"]}],"countries":["CH","FR"],"is_corresponding":false,"raw_author_name":"Ola Svensson","raw_affiliation_strings":["EPFL, Switzerland","EPFL, SWITZERLAND"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"EPFL, Switzerland","institution_ids":["https://openalex.org/I5124864"]},{"raw_affiliation_string":"EPFL, SWITZERLAND","institution_ids":["https://openalex.org/I174424907"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":3.0496,"has_fulltext":false,"cited_by_count":27,"citation_normalized_percentile":{"value":0.91469323,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":90,"max":99},"biblio":{"volume":"58","issue":"5","first_page":"1","last_page":"32"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10551","display_name":"Scheduling and Optimization Algorithms","score":1.0,"subfield":{"id":"https://openalex.org/subfields/2209","display_name":"Industrial and Manufacturing Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10551","display_name":"Scheduling and Optimization Algorithms","score":1.0,"subfield":{"id":"https://openalex.org/subfields/2209","display_name":"Industrial and Manufacturing Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T12288","display_name":"Optimization and Search Problems","score":0.9983999729156494,"subfield":{"id":"https://openalex.org/subfields/1705","display_name":"Computer Networks and Communications"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T12176","display_name":"Optimization and Packing Problems","score":0.9962000250816345,"subfield":{"id":"https://openalex.org/subfields/2209","display_name":"Industrial and Manufacturing Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/job-shop-scheduling","display_name":"Job shop scheduling","score":0.5973803400993347},{"id":"https://openalex.org/keywords/logarithm","display_name":"Logarithm","score":0.5950583219528198},{"id":"https://openalex.org/keywords/flow-shop-scheduling","display_name":"Flow shop scheduling","score":0.5590124130249023},{"id":"https://openalex.org/keywords/approximation-algorithm","display_name":"Approximation algorithm","score":0.5493216514587402},{"id":"https://openalex.org/keywords/closing","display_name":"Closing (real estate)","score":0.5457401275634766},{"id":"https://openalex.org/keywords/scheduling","display_name":"Scheduling (production processes)","score":0.5447304248809814},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.48014089465141296},{"id":"https://openalex.org/keywords/hardness-of-approximation","display_name":"Hardness of approximation","score":0.47874993085861206},{"id":"https://openalex.org/keywords/mathematical-optimization","display_name":"Mathematical optimization","score":0.4610632359981537},{"id":"https://openalex.org/keywords/flow","display_name":"Flow (mathematics)","score":0.4468008875846863},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.4015074372291565},{"id":"https://openalex.org/keywords/combinatorics","display_name":"Combinatorics","score":0.32480907440185547},{"id":"https://openalex.org/keywords/schedule","display_name":"Schedule","score":0.08626294136047363}],"concepts":[{"id":"https://openalex.org/C55416958","wikidata":"https://www.wikidata.org/wiki/Q6206757","display_name":"Job shop scheduling","level":3,"score":0.5973803400993347},{"id":"https://openalex.org/C39927690","wikidata":"https://www.wikidata.org/wiki/Q11197","display_name":"Logarithm","level":2,"score":0.5950583219528198},{"id":"https://openalex.org/C158336966","wikidata":"https://www.wikidata.org/wiki/Q3074426","display_name":"Flow shop scheduling","level":4,"score":0.5590124130249023},{"id":"https://openalex.org/C148764684","wikidata":"https://www.wikidata.org/wiki/Q621751","display_name":"Approximation algorithm","level":2,"score":0.5493216514587402},{"id":"https://openalex.org/C2778775528","wikidata":"https://www.wikidata.org/wiki/Q5135432","display_name":"Closing (real estate)","level":2,"score":0.5457401275634766},{"id":"https://openalex.org/C206729178","wikidata":"https://www.wikidata.org/wiki/Q2271896","display_name":"Scheduling (production processes)","level":2,"score":0.5447304248809814},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.48014089465141296},{"id":"https://openalex.org/C112955886","wikidata":"https://www.wikidata.org/wiki/Q5656275","display_name":"Hardness of approximation","level":3,"score":0.47874993085861206},{"id":"https://openalex.org/C126255220","wikidata":"https://www.wikidata.org/wiki/Q141495","display_name":"Mathematical optimization","level":1,"score":0.4610632359981537},{"id":"https://openalex.org/C38349280","wikidata":"https://www.wikidata.org/wiki/Q1434290","display_name":"Flow (mathematics)","level":2,"score":0.4468008875846863},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.4015074372291565},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.32480907440185547},{"id":"https://openalex.org/C68387754","wikidata":"https://www.wikidata.org/wiki/Q7271585","display_name":"Schedule","level":2,"score":0.08626294136047363},{"id":"https://openalex.org/C111919701","wikidata":"https://www.wikidata.org/wiki/Q9135","display_name":"Operating system","level":1,"score":0.0},{"id":"https://openalex.org/C199539241","wikidata":"https://www.wikidata.org/wiki/Q7748","display_name":"Law","level":1,"score":0.0},{"id":"https://openalex.org/C2524010","wikidata":"https://www.wikidata.org/wiki/Q8087","display_name":"Geometry","level":1,"score":0.0},{"id":"https://openalex.org/C17744445","wikidata":"https://www.wikidata.org/wiki/Q36442","display_name":"Political science","level":0,"score":0.0},{"id":"https://openalex.org/C134306372","wikidata":"https://www.wikidata.org/wiki/Q7754","display_name":"Mathematical analysis","level":1,"score":0.0}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.1145/2027216.2027218","is_oa":false,"landing_page_url":"https://doi.org/10.1145/2027216.2027218","pdf_url":null,"source":{"id":"https://openalex.org/S118992489","display_name":"Journal of the ACM","issn_l":"0004-5411","issn":["0004-5411","1557-735X"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319798","host_organization_name":"Association for Computing Machinery","host_organization_lineage":["https://openalex.org/P4310319798"],"host_organization_lineage_names":["Association for Computing Machinery"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of the ACM","raw_type":"journal-article"},{"id":"pmh:oai:infoscience.epfl.ch:170685","is_oa":true,"landing_page_url":"http://infoscience.epfl.ch/record/170685","pdf_url":null,"source":{"id":"https://openalex.org/S4306400487","display_name":"Infoscience (Ecole Polytechnique F\u00e9d\u00e9rale de Lausanne)","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"","raw_type":"Text"}],"best_oa_location":{"id":"pmh:oai:infoscience.epfl.ch:170685","is_oa":true,"landing_page_url":"http://infoscience.epfl.ch/record/170685","pdf_url":null,"source":{"id":"https://openalex.org/S4306400487","display_name":"Infoscience (Ecole Polytechnique F\u00e9d\u00e9rale de Lausanne)","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"","raw_type":"Text"},"sustainable_development_goals":[{"score":0.6800000071525574,"id":"https://metadata.un.org/sdg/8","display_name":"Decent work and economic growth"}],"awards":[{"id":"https://openalex.org/G2050023448","display_name":null,"funder_award_id":"200020-122110/1","funder_id":"https://openalex.org/F4320320924","funder_display_name":"Schweizerischer Nationalfonds zur F\u00f6rderung der Wissenschaftlichen Forschung"},{"id":"https://openalex.org/G4313770918","display_name":null,"funder_award_id":"11099","funder_id":"https://openalex.org/F4320321942","funder_display_name":"Hasler Stiftung"},{"id":"https://openalex.org/G5529985077","display_name":null,"funder_award_id":"2.26E+11","funder_id":"https://openalex.org/F4320334678","funder_display_name":"European Research Council"}],"funders":[{"id":"https://openalex.org/F4320320924","display_name":"Schweizerischer Nationalfonds zur F\u00f6rderung der Wissenschaftlichen Forschung","ror":"https://ror.org/00yjd3n13"},{"id":"https://openalex.org/F4320321942","display_name":"Hasler Stiftung","ror":"https://ror.org/04m3t9183"},{"id":"https://openalex.org/F4320334678","display_name":"European Research Council","ror":"https://ror.org/0472cxd90"}],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":26,"referenced_works":["https://openalex.org/W5599802","https://openalex.org/W61923620","https://openalex.org/W1488422606","https://openalex.org/W1501934796","https://openalex.org/W1824801789","https://openalex.org/W1969964129","https://openalex.org/W1974874234","https://openalex.org/W1980986261","https://openalex.org/W1991124379","https://openalex.org/W2000619341","https://openalex.org/W2006905044","https://openalex.org/W2007315235","https://openalex.org/W2012391569","https://openalex.org/W2022392080","https://openalex.org/W2053608913","https://openalex.org/W2084427019","https://openalex.org/W2087811837","https://openalex.org/W2091885230","https://openalex.org/W2132991500","https://openalex.org/W2134833035","https://openalex.org/W2159255281","https://openalex.org/W2170050590","https://openalex.org/W2576116471","https://openalex.org/W2808376720","https://openalex.org/W3015891365","https://openalex.org/W3137060907"],"related_works":["https://openalex.org/W2185192838","https://openalex.org/W2967782293","https://openalex.org/W2955323683","https://openalex.org/W1564838499","https://openalex.org/W2069961172","https://openalex.org/W2559484340","https://openalex.org/W26892725","https://openalex.org/W2165758382","https://openalex.org/W1971939018","https://openalex.org/W2140584489"],"abstract_inverted_index":{"We":[0],"consider":[1],"several":[2,79],"variants":[3],"of":[4,71,74,112,139],"the":[5,30,72,83,88,96,109,132,137,147,153],"job":[6,43,102],"shop":[7],"problem":[8,15,76,148],"that":[9,37,93,146],"is":[10,39,56,86,134,143],"a":[11,46,57],"fundamental":[12],"and":[13,59,77,152],"classical":[14],"in":[16,68,82],"scheduling.":[17],"The":[18,104],"currently":[19],"best":[20],"approximation":[21,98],"algorithms":[22],"have":[23,159],"worse":[24],"than":[25,49],"logarithmic":[26],"performance":[27],"guarantee,":[28],"but":[29],"only":[31],"previously":[32],"known":[33],"inapproximability":[34,91,127],"result":[35,92],"says":[36],"it":[38],"NP-hard":[40],"to":[41,120,135],"approximate":[42],"shops":[44],"within":[45],"factor":[47],"less":[48],"5/4.":[50],"Closing":[51],"this":[52,75],"big":[53],"approximability":[54],"gap":[55],"well-known":[58],"long-standing":[60],"open":[61,80],"problem.":[62],"This":[63],"article":[64],"closes":[65],"many":[66],"gaps":[67],"our":[69],"understanding":[70],"hardness":[73],"answers":[78],"questions":[81],"literature.":[84],"It":[85,142],"shown":[87,145],"first":[89],"nonconstant":[90],"almost":[94],"matches":[95],"best-known":[97],"algorithm":[99],"for":[100,108],"acyclic":[101],"shops.":[103],"same":[105],"bounds":[106],"hold":[107],"general":[110],"version":[111],"flow":[113],"shops,":[114],"where":[115],"jobs":[116],"are":[117,129],"not":[118],"required":[119],"be":[121],"processed":[122],"on":[123],"each":[124],"machine.":[125],"Similar":[126],"results":[128],"obtained":[130],"when":[131],"objective":[133],"minimize":[136],"sum":[138],"completion":[140],"times.":[141],"also":[144],"with":[149,156],"two":[150],"machines":[151,158],"preemptive":[154],"variant":[155],"three":[157],"no":[160],"PTAS.":[161]},"counts_by_year":[{"year":2026,"cited_by_count":2},{"year":2025,"cited_by_count":1},{"year":2024,"cited_by_count":1},{"year":2022,"cited_by_count":3},{"year":2021,"cited_by_count":3},{"year":2020,"cited_by_count":2},{"year":2019,"cited_by_count":4},{"year":2018,"cited_by_count":2},{"year":2017,"cited_by_count":1},{"year":2016,"cited_by_count":2},{"year":2015,"cited_by_count":2},{"year":2013,"cited_by_count":4}],"updated_date":"2026-06-11T09:08:48.828518","created_date":"2025-10-10T00:00:00"}
