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Title:Time restrictions in forest operations planning
Authors:Kepic, Boštjan (Author)
Krč, Janez (Mentor) More about this mentor... New window
Files:.pdf Bostjan_Kepic.pdf (4,11 MB)
 
Language:English
Work type:Master's thesis (m2)
Tipology:2.09 - Master's Thesis
Organization:FPŠ - Graduate School
Abstract:This master’s thesis deals with annual harvest operations (AHO) planning with consideration of time restrictions. We developed five models of binary integer linear programming (BILP) that schedule working groups to harvest unit areas (HUAs) according to the lowest cost possible. Total AHO costs include felling and skidding costs, transportation costs, and machine relocation costs. The first model is based on the presumption that harvesting can be planned and executed freely throughout the year. In other four, scheduling was subject to time restrictions in HUAs and differed according to the extent of time restrictions. The second model takes into account time restrictions due to unfavourable natural conditions, the third model due to disturbance-free areas of animal species, the fourth and fifth model concurrently include the impact of time restrictions due to natural conditions and disturbance-free areas. The annual workplace time in Model 2 is reduced by 14.2 %, in Model 3 by 16.9 %, in Model 4 by 29.3 % and in Model 5 by 42.3 %. The model tool used to test all the models was designed in Microsoft Excel. All five models were tested with OpenSolver 2.7.1 software. Increasing the extent of time restrictions in forest operations reduces the utilization of the annual workplace time. In testing the second model, we demonstrated that with proper organisation of an AHO plan the planner can influence the working days fallout. In the other three models, we were able to ensure the implementation of AHO plan by introducing extra working groups. Further, we confirmed that time restrictions affect the scheduling of the working groups and the sequencing of tasks. The increases in total AHO costs were explained as an increase in working groups’ costs due to lower utilization rate, an increase in depreciation costs of machines and costs due to unrealized allowable annual cut and timber sales planned for the current year. We tested each model on two examples.
Keywords:time restrictions, binary integer programming, forestry, annual harvest operations planning, harvesting, scheduling working teams
Year of publishing:2016
Source:Nova Gorica
COBISS_ID:4497915 Link is opened in a new window
URN:URN:SI:UNG:REP:W0BOKMDZ
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Downloads:140
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Secondary language

Language:Slovenian
Title:Časovne omejitve načrtovanja izvedbe gozdarskih del
Abstract:Magistrska naloga obravnava vpliv časovnih omejitev na načrtovanje letne izvedbe pridobivanja lesa (fazi sečnje in spravila lesa). Izdelali smo pet modelov binarnega celoštevilskega linearnega programiranja (BILP) za razmeščanje delovnih skupin v oddelke, glede na najmanjše skupne stroške. Ti vključujejo stroške izvedbe sečnje in spravila lesa, potne stroške in stroške premikov strojev. V prvem modelu smo predpostavili, da je čas proizvodnje poljuben. Ostali štirje modeli so upoštevali časovne omejitve izvajanja gozdne proizvodnje tako, da so se le te stopnjevale v obsegu. Drugi model upošteva vpliv neugodnih naravnih razmer, tretji model vpliv mirnih con živalskih vrst, četrti in peti model pa hkraten vpliv neugodnih naravnih razmer in mirnih con. Razpoložljiv letni delovni čas je zaradi časovnih omejitev pri modelu 2 zmanjšan za 14,2 %, pri modelu 3 za 16,9 %, pri modelu 4 za 29,3 % in pri modelu 5 za 42,3 %. Modelno orodje za preizkus modelov je zasnovano v Microsoft Excelu. Modele smo preizkusili s programskim orodjem OpenSlover 2.7.1. Povečevanje obsega časovnih omejitev izvedbe gozdne proizvodnje zmanjšuje letni izkoristek delovnega časa. S preizkusom drugega modela smo pokazali, da načrtovalec letne gozdne proizvodnje z ustrezno organizacijo dela lahko vpliva na izkoristek delovnega časa. Pri preizkusih ostalih treh modelov je bilo zaradi časovnih omejitev letno izvedbo pridobivanja lesa možno izvesti le z uvedbo dodatnih delovnih skupin. Povečane skupne stroške izvajanja letne gozdne proizvodnje zaradi časovnih omejitev je možno opravičiti z nezmožnostjo poseka in prodaje lesa, povečanimi stroški delovnih skupin in višjimi stroški amortizacije za mehanizacijo. Vsak model smo testirali na dveh primerih.
Keywords:časovne omejitve, binarno celoštevilsko linearno programiranje, načrtovanje poseka lesa, gozdarstvo, gozdna proizvodnja, razmeščanje delovnih skupin


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