{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T06:46:38Z","timestamp":1782197198896,"version":"3.54.5"},"reference-count":13,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T00:00:00Z","timestamp":1782086400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T00:00:00Z","timestamp":1782086400000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council of Canada","doi-asserted-by":"publisher","award":["RGPIN\/03232\u20102022"],"award-info":[{"award-number":["RGPIN\/03232\u20102022"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Transfusion"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Blood banks often use simple ordering rules that replenish stock to a target level when inventory falls below a trigger point. However, for products such as Low\u2010Titer group O Whole Blood (LTOWB), where utilization is intermittent, simple rules may not always be effective. This paper evaluates ordering policies for blood products with intermittent (\u201cspotty\u201d) demand.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Study Design and Methods<\/jats:title>\n                    <jats:p>LTOWB inventory was evaluated under zero\u2010inflated Poisson (ZIP) (i.e., spotty) demand. Four strategies were compared against an exact benchmark: (i) a classical reorder\u2010point\/order\u2010up\u2010to policy, (ii) a scenario\u2010based rolling horizon heuristic (Sc\u2010RHA), (iii) model\u2010based approximate dynamic programming (ADP), and (iv) model\u2010free reinforcement learning using Proximal Policy Optimization (PPO). Performance was assessed using total expected cost relative to the exact solution.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Simple reorder\u2010point\/order\u2010up\u2010to policies work well when demand is consistent or regular. When expected daily demand is approximately 1.0 unit\/day, this simple policy is close to optimal. Sc\u2010RHA reduces the threshold for reliable performance to approximately 0.4\u2009units\/day by incorporating short\u2010term age and demand information. ADP remains stable and near\u2010optimal across the full demand range, including highly sparse settings. However, PPO is effective only when an extremely large amount of simulated training data is available, which is operationally impractical in typical LTOWB settings.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Centers with robust demand of at least 1.0 unit\/day can safely rely on simple reorder\u2010point\/order\u2010up\u2010to policies. For locations with demand between 0.4 and 1.0 unit\/day, Sc\u2010RHA provides an age\u2010aware alternative with modest added complexity. For extreme sparsity, ADP becomes the most appropriate approach.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/trf.70298","type":"journal-article","created":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T05:51:50Z","timestamp":1782193910000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Size (and frequency) matter: Evaluating the best management practices for blood products with spotty demand"],"prefix":"10.1111","author":[{"given":"S.","family":"Safavi","sequence":"first","affiliation":[{"name":"Dalhousie University  Halifa Nova Scotia Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John T.","family":"Blake","sequence":"additional","affiliation":[{"name":"Dalhousie University  Halifa Nova Scotia Canada"},{"name":"Canadian Blood Services  Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,6,22]]},"reference":[{"key":"e_1_2_10_2_1","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1111\/j.1537-2995.2008.01996.x","article-title":"Blood platelet production: a novel approach for practical optimisation","volume":"49","author":"Van Dijk N","year":"2009","journal-title":"Transfusion"},{"key":"e_1_2_10_3_1","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1111\/j.1537-2995.2008.02061.x","article-title":"On the use of operational research for managing platelet inventory and ordering","volume":"49","author":"Blake JT","year":"2009","journal-title":"Transfusion"},{"key":"e_1_2_10_4_1","doi-asserted-by":"crossref","first-page":"S176","DOI":"10.1111\/trf.15601","article-title":"An international survey on the use of low titer group O whole blood for the resuscitation of civilian trauma patients in 2020","volume":"60","author":"Yazer MH","year":"2020","journal-title":"Transfusion"},{"issue":"10","key":"e_1_2_10_5_1","doi-asserted-by":"crossref","first-page":"2280","DOI":"10.1111\/trf.14771","article-title":"Safety profile of uncross matched, cold\u2010stored, low\u2010titer, group O+ whole blood in civilian trauma patients","volume":"58","author":"Seheult JN","year":"2018","journal-title":"Transfusion"},{"issue":"5","key":"e_1_2_10_6_1","doi-asserted-by":"crossref","first-page":"1576","DOI":"10.1016\/j.injury.2022.01.043","article-title":"Implementation of a low\u2010titer stored whole blood transfusion program for civilian trauma patients: early experience and logistical challenges","volume":"53","author":"Barmparas G","year":"2022","journal-title":"Injury"},{"key":"e_1_2_10_7_1","doi-asserted-by":"crossref","DOI":"10.1016\/j.ordal.2025.200482","article-title":"Inventory management of perishables under zero\u2010inflated Poisson demand","volume":"45","author":"Safavi S","year":"2025","journal-title":"Operations Research, Data Analytics and Logistics"},{"issue":"4","key":"e_1_2_10_8_1","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1287\/msom.1110.0334","article-title":"Inventory management of platelets in hospitals: optimal inventory policy for perishable products with regular and optional expedited replenishments","volume":"13","author":"Zhou D","year":"2011","journal-title":"Manuf Serv Oper Manag"},{"issue":"7","key":"e_1_2_10_9_1","doi-asserted-by":"crossref","first-page":"1318","DOI":"10.1111\/trf.17418","article-title":"Evaluating the inventory impact of utilizing low titer platelets in regional hospitals","volume":"63","author":"Blake JT","year":"2023","journal-title":"Transfusion"},{"issue":"2","key":"e_1_2_10_10_1","doi-asserted-by":"crossref","first-page":"640","DOI":"10.1016\/j.ejor.2023.03.007","article-title":"Supporting platelet inventory management decisions: what is the effect of extending platelets' shelf life?","volume":"310","author":"Dillon M","year":"2023","journal-title":"European Journal of Operational Research"},{"key":"e_1_2_10_11_1","unstructured":"SafaviS BlakeJT.Managing perishable blood inventories: a scenario\u2010based rolling horizon approach for LTOWB under zero\u2010inflated Poisson demand. [Submitted\u2010Under review]."},{"issue":"1","key":"e_1_2_10_12_1","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1287\/ijoc.2023.0245","article-title":"Platelet inventory management with approximate dynamic programming","volume":"38","author":"Abouee\u2010Mehrizi H","year":"2025","journal-title":"INFORMS Journal on Computing"},{"key":"e_1_2_10_13_1","unstructured":"SafaviS BlakeJT.A reinforcement learning framework for managing perishable healthcare inventories under sparse demand. [Submitted\u2010Under review]."},{"issue":"3","key":"e_1_2_10_14_1","doi-asserted-by":"crossref","first-page":"1609","DOI":"10.1007\/s10479-025-06551-6","article-title":"Going faster to see further: graphics processing unit\u2010accelerated value iteration and simulation for perishable inventory control using JAX","volume":"349","author":"Farrington J","year":"2025","journal-title":"Annals of Operations Research"}],"container-title":["Transfusion"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/trf.70298","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1111\/trf.70298","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/trf.70298","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T05:51:59Z","timestamp":1782193919000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/trf.70298"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,22]]},"references-count":13,"alternative-id":["10.1111\/trf.70298"],"URL":"https:\/\/doi.org\/10.1111\/trf.70298","archive":["Portico"],"relation":{},"ISSN":["0041-1132","1537-2995"],"issn-type":[{"value":"0041-1132","type":"print"},{"value":"1537-2995","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,22]]},"assertion":[{"value":"2026-03-05","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-05-27","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-06-22","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"trf.70298"}}