1 / 18

Logistics cost

Logistics cost. Componenti del costo logistico.

abie
Télécharger la présentation

Logistics cost

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Logistics cost

  2. Componenti del costo logistico Costi di trasporto(in ingresso, intra-company. in uscita) Costi di magazzino(immagazinamento e deposito dei prodotti, localizzazione del deposito e della azienda) Costo di mantenimento scorte(capitale per materie prime, WIP, prodotti finiti, scarti) Costi di acquisto/produzione lotti (movimentazione materiali, messa a punto linee) Costo degli imballi per trasporto e movimentazione (pallet, materiali da imballaggio, altri) Costi amministrativi/di struttura(direzione, personale amministrativo, sistemi informativi, elaborazione ordini)

  3. Consumption Storage Production Time space diagrams Consider a simple Product to Consumption Network Primary Tradeoffs: Moving (Handle, Transport)/Holding (Rent, Inventory)

  4. nd Cumulative count curve Shipments Arrivals Horizontal distances • Transit time tm • Headway hi Vertical distances • Items waiting transport nw • Items in transit nt • Items at destination nd Cumulative Count of Items nw nt hi D tm D Time

  5. Logistics cost LC function LC (per item) = Holding Costs + Moving Costs Holding Costs = Rent Cost + Inventory Cost Moving Costs = Transport Cost + Handling Cost LC (per item) = (R + I) + (T + H)

  6. Rent cost R (€/item) Function of max inventory Captures facility costs Not affected by the item by item flow AnnualRentCost = cr Dhmax R = cr hmax D = Annual demand (items/time) cr = Rent cost (€/item-time) hmax = Maximum headway (time)

  7. Inventory cost I (€/item) Function of delay to items. Captures capital costs, insurance, etc. Implies that each time period matters equally Constant to each time period (linear) Annual Inventory Cost = ci D(1/2ħ + tm) I = ci(1/2ħ + tm) ci = Inventory cost (€/item-time) ħ = average headway tm =Transit time

  8. Transport cost T (€/item) Shipment size u has a shipment cost s s = cf + cvv the cost of n shipments is ns =Sn(cf + cvvi) =ncf + cvSnvi =ncf + cvD The transport cost T is T = cf (n/D) + cv = cf /ū+ cv T decreases with increase in average shipment size ū.

  9. Nomenclature cf = Fixed transport cost (€/shipment) cv = Variable transport cost (€/item) u = Shipment size (items) D = Annual number of items shipped = Snu ū = D/n average shipment size n = number of annual shipments

  10. Transport costs T with headways h Number of items in an average shipment ū = Dħ T decreases with increase in average ħ I increases with ħ T = cf /Dħ + cv = cf /ū + cv cf = Fixed transport cost (€/shipment) cv = Variable transport cost (€/item)

  11. Transport costs and distance “Fixed” costs cf are variable with number of delivery stops ns and distance d Variable costs have a fixed component and a linear component variable with distance d cf = cfs (1 + ns ) + cfdd cv = cvs + cvdd T = cf /ū + cv T = cfs (1 + ns )/ū + cfdd/ū + cvs + cvdd Marginal cost of an additional item ignore cvd

  12. Transport Cost per Shipment CMAX= Maximum capacity for transport mode (items) ft(v) cv cf Shipment Size CMAX 2CMAX 3CMAX Transport costs in relation to capacity ft(u) is sub-additive: ft(u1+u2)≤ ft(u1)+ft(u2) cvuMAX<<cf

  13. Mode 1 Transport Cost per Shipment Mode 2 Mode 3 cv cf Shipment Size Transport costs with multiple modes

  14. Handling costs H (€/item) Loading items into boxes, pallets, containers, etc. • If handled individually – linear with each item • If handled in batches – fixed & variable components H = cfh + cvhCh Ch= capacity (items) for load unit h

  15. Moving costs T + H (€/item) T + H = cf/ū + (cv + cfh /ChMAX + cvh) T + H= cfs(1+ ns)/ū + cfdd/ū + cvs+ cfh/ChMAX+ cvh Generally handling costs are subsumed within transport costs as long as D>>ChMAX (total shipment size is much greater than pallet)

  16. Total logistics cost LC function LC(€/item) = crhmax+ 1/2ciħ+ citm + cfs(1+ns)/ū + cfdd/ū + cvs cr = Rent cost (€/item-time) ci= Inventory cost (€/item-time) tm =Transit time hMAX= Maximum headway (time) cfs= Fixed cost per stop (€/stop) cfd= Cost per distance (€/distance) cvs= Marginal cost per item ns= Number of delivery stops d = distance ū = D/n = Dħ average shipment size

  17. Total logistics cost function VMAX = Maximum capacity for transport mode (items)

  18. Optimum shipment and headway LC(€/item) = crhmax+ 1/2ciħ+ citm + cfs(1+ns)/ū + cfdd/ū + cvs ū = D/n = Dħ average shipment size LC(€/item) = crhmax+ 1/2ciū/D+ citm + cfs(1+ns)/ū + cfdd/ū + cvs dLC/dv = 1/2ci/D - cfs[(1+ns) + cfdd]/ū2 = 0 ū* = {2cfsD[(1+ns) + cfdd]/ci}1/2 The size ū* increases with respect to the square root of D, and the square root of d. The optimum delivery frequency D/ū* will increase in proportion to the square root of Dand will fall with respect to the square root of d.

More Related