Here are some key ways the conflicting goals of different partners and facilities in Barilla's supply chain can be addressed:
- Improve information sharing and coordination across the entire supply chain from manufacturers to retailers. Visibility into demand data can help align forecasting and operations.
- Adopt a Vendor Managed Inventory or collaborative planning approach to transfer responsibility for demand planning to Barilla and better integrate facilities/partners.
- Reduce complexity by streamlining SKU numbers and product varieties to improve forecasting accuracy and production planning.
- Pursue Just-In-Time manufacturing and distribution methods within Barilla's control to minimize inventories while still meeting customer needs. Overall, prioritizing integration, information sharing, and reducing
Dell uses a build-to-order inventory model where it receives customer orders and money before building products to ensure customization. It uses "revolvers" or supplier warehouses near its assembly plants to buffer long supplier lead times. Dell also uses a "value chain" program for collaborative information sharing with suppliers. This just-in-time model reduces costs from avoiding excess inventory and obsolete goods while allowing Dell to introduce new products and target low prices.
O documento resume as conclusões do II Encontro Nacional sobre Política de Ensino de Línguas Estrangeiras sobre os desafios e propostas para melhorar o ensino de línguas no Brasil, incluindo garantir o acesso de qualidade para todos os alunos, incentivar o estudo de mais de uma língua, e apoiar a formação continuada dos professores.
Dell pioneered an innovative inventory management system focused on minimizing inventory and maximizing profitability. The system utilizes a build-to-order philosophy with just-in-time inventory practices and zero inventory warehouses. Components are sourced globally from suppliers and assembled only after receiving customer orders. This allows Dell to fulfill customized orders within days while avoiding the costs of storing unsold inventory. The system transformed Dell's supply chain from maintaining weeks of inventory to generating over $15 million in sales daily with under one day of inventory on hand.
This document discusses various facility layout concepts and approaches. It begins by defining facility layout as the process of determining the placement of departments, workgroups, workstations, machines, and stockholding points within a facility based on objectives, demand estimates, processing requirements, and space constraints. The document then covers criteria for a good layout, basic layout formats including process, product, group technology, and fixed-position layouts. It provides examples of developing process and product layouts, including the use of computer models, line balancing concepts, and cellular manufacturing layouts. The key objectives are to optimize material flow, worker efficiency, flexibility, and space utilization.
Dell PC & Laptop's Supply Chain ManagementFPT Univesity
Dell's supply chain management involves managing quality, demand, logistics, and customer relationships. Dell shares supply chain information with suppliers and assesses supplier performance. It uses systems like ValueChain to coordinate inventory levels and quality metrics. Dell also forecasts demand using techniques like neural networks. Its build-to-order and configure-to-order models help match production to customer orders. Dell integrates supply and demand planning to reduce inventory levels.
Started in 1984 by Michael Dell in his dorm room at the University of Texas, Dell grew to become the 2nd largest computer company, worth $17.3 billion. Dell's success stems from its direct sales model, building computers to customer order, and integrated suppliers. This allows Dell to cut costs, build customer relationships, deliver customized products, maximize inventory velocity, and minimize forecasting needs through collaboration at every level of the supply chain.
This document contains profiles for four different customer segments: Young People, Tourists, Families, and Foodies.
For each segment, it provides personal and professional objectives, a description of a typical day, and a profile description. It also includes empathy maps that describe what is important to each segment from their perspective in terms of wants, needs, and experiences related to dining out.
The customer segments are: Young People (Joana Teixeira), Tourists (Susan Collins), Families (Teixeira Family), and Foodies (Jane Sullivan). Each profile provides insights for better understanding these groups and their priorities when choosing restaurants.
Here are some key ways the conflicting goals of different partners and facilities in Barilla's supply chain can be addressed:
- Improve information sharing and coordination across the entire supply chain from manufacturers to retailers. Visibility into demand data can help align forecasting and operations.
- Adopt a Vendor Managed Inventory or collaborative planning approach to transfer responsibility for demand planning to Barilla and better integrate facilities/partners.
- Reduce complexity by streamlining SKU numbers and product varieties to improve forecasting accuracy and production planning.
- Pursue Just-In-Time manufacturing and distribution methods within Barilla's control to minimize inventories while still meeting customer needs. Overall, prioritizing integration, information sharing, and reducing
Dell uses a build-to-order inventory model where it receives customer orders and money before building products to ensure customization. It uses "revolvers" or supplier warehouses near its assembly plants to buffer long supplier lead times. Dell also uses a "value chain" program for collaborative information sharing with suppliers. This just-in-time model reduces costs from avoiding excess inventory and obsolete goods while allowing Dell to introduce new products and target low prices.
O documento resume as conclusões do II Encontro Nacional sobre Política de Ensino de Línguas Estrangeiras sobre os desafios e propostas para melhorar o ensino de línguas no Brasil, incluindo garantir o acesso de qualidade para todos os alunos, incentivar o estudo de mais de uma língua, e apoiar a formação continuada dos professores.
Dell pioneered an innovative inventory management system focused on minimizing inventory and maximizing profitability. The system utilizes a build-to-order philosophy with just-in-time inventory practices and zero inventory warehouses. Components are sourced globally from suppliers and assembled only after receiving customer orders. This allows Dell to fulfill customized orders within days while avoiding the costs of storing unsold inventory. The system transformed Dell's supply chain from maintaining weeks of inventory to generating over $15 million in sales daily with under one day of inventory on hand.
This document discusses various facility layout concepts and approaches. It begins by defining facility layout as the process of determining the placement of departments, workgroups, workstations, machines, and stockholding points within a facility based on objectives, demand estimates, processing requirements, and space constraints. The document then covers criteria for a good layout, basic layout formats including process, product, group technology, and fixed-position layouts. It provides examples of developing process and product layouts, including the use of computer models, line balancing concepts, and cellular manufacturing layouts. The key objectives are to optimize material flow, worker efficiency, flexibility, and space utilization.
Dell PC & Laptop's Supply Chain ManagementFPT Univesity
Dell's supply chain management involves managing quality, demand, logistics, and customer relationships. Dell shares supply chain information with suppliers and assesses supplier performance. It uses systems like ValueChain to coordinate inventory levels and quality metrics. Dell also forecasts demand using techniques like neural networks. Its build-to-order and configure-to-order models help match production to customer orders. Dell integrates supply and demand planning to reduce inventory levels.
Started in 1984 by Michael Dell in his dorm room at the University of Texas, Dell grew to become the 2nd largest computer company, worth $17.3 billion. Dell's success stems from its direct sales model, building computers to customer order, and integrated suppliers. This allows Dell to cut costs, build customer relationships, deliver customized products, maximize inventory velocity, and minimize forecasting needs through collaboration at every level of the supply chain.
This document contains profiles for four different customer segments: Young People, Tourists, Families, and Foodies.
For each segment, it provides personal and professional objectives, a description of a typical day, and a profile description. It also includes empathy maps that describe what is important to each segment from their perspective in terms of wants, needs, and experiences related to dining out.
The customer segments are: Young People (Joana Teixeira), Tourists (Susan Collins), Families (Teixeira Family), and Foodies (Jane Sullivan). Each profile provides insights for better understanding these groups and their priorities when choosing restaurants.
Dell's supply chain management model focuses on procurement, customer order fulfillment, and manufacturing to minimize inventory and risks. It procures components based on customer orders and manufactures products through a cycle linked directly to orders, reducing finished inventory compared to traditional supply chain models. This effective direct sales approach increases returns on capital employed.
Barilla Spa: A case on Supply Chain IntegrationHimadri Singha
Barilla is the world's largest pasta producer. It faced issues like extreme demand fluctuations, high inventory costs, and low service levels. It implemented a Just-in-Time Distribution system where it took over inventory management from distributors. Pilots showed lower inventory, higher service levels. Implementation with other distributors included daily electronic data sharing. The system reduced costs and improved supply chain visibility for both Barilla and distributors.
This document discusses the Theory of Constraints (TOC), a management approach that focuses on actively managing constraints that limit an organization's ability to meet goals. It identifies three main types of constraints - bottlenecks, capacity constraints, and demand constraints. A bottleneck is defined as the resource with the lowest capacity in a process. The TOC involves identifying bottlenecks, exploiting them to maximize throughput, and subordinating other decisions to bottleneck management. Key principles include focusing on bottleneck utilization and flow rather than non-bottleneck resources, and pacing work release according to bottleneck capacity.
The document provides information about master scheduling, including:
1) Master scheduling is the process of producing a supply plan to schedule specific items or services within a given time period to meet demand.
2) It balances demand and supply at a detailed level through a master production schedule, which anticipates the build schedule for products and customer orders.
3) The master scheduling process involves calculating projected on-hand inventory, determining production quantities and timing to meet demand while satisfying resource constraints, and revising the schedule until a feasible plan is developed.
The document discusses various lot sizing techniques used to determine optimal batch sizes for production and purchasing. It describes techniques like economic order quantity (EOQ), fixed order quantity (FOQ), lot-for-lot (LFL), periods of supply (POS), period order quantity (POQ), least unit cost (LUC), least total cost (LTC), and part period balancing (PPB). Examples are provided to illustrate how each technique works and the optimal lot size is calculated. The goal of lot sizing is to minimize total inventory costs by balancing setup/ordering costs and carrying costs.
Kristen runs a cookie business called Kristen's Cookie Co. and has some questions about operations. She can currently fill 6 dozen cookies per hour which is the bottleneck in her process. In 4 hours of baking each night she could fill 22 orders. Each order takes her own time and her roommate's time to complete. She asks if she should offer volume discounts and how many food processors and baking sheets she will need. Changes like better, faster production or lower costs are also considered along with adding another oven.
Meditech is facing issues with on-time delivery of surgical equipment to customers. They are currently delivering products over six weeks late. This is unacceptable in their industry where timely delivery is important. The key causes are a bullwhip effect in the supply chain from poor demand forecasting, long lead times, and frequent new product introductions. Communication issues between departments also contribute to distorted information and panic ordering from distributors.
This document discusses HP's DeskJet printer supply chain in 1990. It describes the manufacturing and distribution process, including production at a facility in Vancouver and shipping to distribution centers in the US, Europe, and Far East. It identifies challenges like forecast errors, long transportation lead times, and meeting demand across different regions. Solutions proposed include making forecasts more accurate using historical data, potentially opening a new factory or distribution center in Europe, and expediting transportation via air to reduce lead times.
7-Eleven uses distribution centers in Japan rather than direct store delivery to consolidate orders from multiple stores. This allows for shorter replenishment times and better tracking of sales data. Receiving products from distribution centers reduces transportation costs for 7-Eleven compared to direct delivery from various suppliers, as distribution centers can consolidate partial loads into full truckloads. This centralized distribution model simplifies ordering and delivery for 7-Eleven's many store locations across Japan.
Barilla, a pasta manufacturer, wants to reduce inventory levels and lead times through a Just-In-Time Delivery (JITD) system with distributors and salespeople. However, distributors want inventory control and independence from Barilla, while salespeople fear reduced responsibilities and bonuses. To address these objectives, the proposal involves piloting JITD with willing distributors to demonstrate benefits. It also proposes making distributors joint owners of sales data or having Barilla representatives monitor inventory. For salespeople, the proposal restructures incentives and redesigns jobs to emphasize inventory reductions and data collection. Barilla would take a long-term partnership approach and help distributors achieve their strategic objectives to build trust.
This document provides an overview of scheduling in production. It discusses what scheduling is, examples of scheduling like timetabling courses and assigning hospital shifts. The objectives of scheduling are to maximize throughput while maintaining balance and priorities. Master production scheduling is introduced as planning completions of end items. The objectives of MPS are to maintain inventories, customer service and due dates. Problems of sequencing jobs like shortest processing time are also covered with an example.
The document provides an overview of simulation modeling. It discusses that simulation is used to mathematically imitate real-world situations in order to study their properties, operating characteristics, and draw conclusions. It outlines the seven steps of simulation as defining a problem, introducing important variables, constructing a simulation model, specifying variable values, conducting the simulation, examining results, and selecting the best course of action. Monte Carlo simulation is described as using random sampling to experiment on probabilistic elements. Two examples of Monte Carlo simulation are provided to analyze inventory management and power generator maintenance costs.
This presentation explains about the Operations Management concept Reorder point, different cases with examples, fixed order interval model, single period model etc.
The document discusses Just-In-Time (JIT), an inventory strategy developed in Japan after World War II. JIT aims to increase efficiency and reduce costs by receiving goods only as needed in the production process, keeping stock levels minimal. Toyota was the first to successfully implement JIT in the 1970s. The key aspects of JIT are receiving stocks just before production and maintaining close supplier relationships, with no production occurring without a customer order. Major benefits of JIT include reduced costs from less tied-up capital and storage space.
This document summarizes a report on Dell presented by Gourav J. It provides an introduction to Dell, outlines its history beginning in 1984, and identifies its current CEO as Michael Dell. The document also describes Dell's vision, mission, direct sales model, supply chain and logistics processes, and concludes that Dell's success stems from its direct sales and build-to-order business model enabled by its use of information technology.
This document discusses inventory management, supply contracts, and risk pooling. It addresses issues like inventory management policies, demand uncertainty, centralized vs decentralized systems, and practical inventory management challenges. It provides an example of calculating optimal order quantity using the economic order quantity model and discusses how demand uncertainty, initial inventory levels, and supply contracts can impact profits. Supply contracts that include a buy-back agreement can increase profits for both manufacturers and distributors by better managing risks from demand uncertainty.
The document discusses the production processes of American Connector Company (ACC) and Denso Corporation's Kawasaki plant. ACC operated 6 plants globally, emphasizing quality and customization which made up 15% of production. The Sunnyvale plant produced 4500 connector models and had undergone expansions. Kawasaki aimed for 99% utilization and customer complaints of less than 1 per million units. It used standardized designs and processes to maximize efficiency and yield. A comparison of ACC and Kawasaki in 1986 and 1991 showed Kawasaki had lower costs due to its lean production approach.
Basic terminologies and EOQ models of Inventory TheoryShashank Naruka
This document provides an overview of inventory theory and economic order quantity (EOQ) models. It defines key inventory terminology like demand, lead time, reorder point, and carrying costs. It then explains the assumptions and calculations for the basic EOQ model, which aims to minimize total inventory costs by balancing ordering and carrying costs. The document also presents a model that accounts for variable demand rates over time. It concludes by listing references for further information on inventory theory and EOQ concepts.
Dell's supply chain management model focuses on procurement, customer order fulfillment, and manufacturing to minimize inventory and risks. It procures components based on customer orders and manufactures products through a cycle linked directly to orders, reducing finished inventory compared to traditional supply chain models. This effective direct sales approach increases returns on capital employed.
Barilla Spa: A case on Supply Chain IntegrationHimadri Singha
Barilla is the world's largest pasta producer. It faced issues like extreme demand fluctuations, high inventory costs, and low service levels. It implemented a Just-in-Time Distribution system where it took over inventory management from distributors. Pilots showed lower inventory, higher service levels. Implementation with other distributors included daily electronic data sharing. The system reduced costs and improved supply chain visibility for both Barilla and distributors.
This document discusses the Theory of Constraints (TOC), a management approach that focuses on actively managing constraints that limit an organization's ability to meet goals. It identifies three main types of constraints - bottlenecks, capacity constraints, and demand constraints. A bottleneck is defined as the resource with the lowest capacity in a process. The TOC involves identifying bottlenecks, exploiting them to maximize throughput, and subordinating other decisions to bottleneck management. Key principles include focusing on bottleneck utilization and flow rather than non-bottleneck resources, and pacing work release according to bottleneck capacity.
The document provides information about master scheduling, including:
1) Master scheduling is the process of producing a supply plan to schedule specific items or services within a given time period to meet demand.
2) It balances demand and supply at a detailed level through a master production schedule, which anticipates the build schedule for products and customer orders.
3) The master scheduling process involves calculating projected on-hand inventory, determining production quantities and timing to meet demand while satisfying resource constraints, and revising the schedule until a feasible plan is developed.
The document discusses various lot sizing techniques used to determine optimal batch sizes for production and purchasing. It describes techniques like economic order quantity (EOQ), fixed order quantity (FOQ), lot-for-lot (LFL), periods of supply (POS), period order quantity (POQ), least unit cost (LUC), least total cost (LTC), and part period balancing (PPB). Examples are provided to illustrate how each technique works and the optimal lot size is calculated. The goal of lot sizing is to minimize total inventory costs by balancing setup/ordering costs and carrying costs.
Kristen runs a cookie business called Kristen's Cookie Co. and has some questions about operations. She can currently fill 6 dozen cookies per hour which is the bottleneck in her process. In 4 hours of baking each night she could fill 22 orders. Each order takes her own time and her roommate's time to complete. She asks if she should offer volume discounts and how many food processors and baking sheets she will need. Changes like better, faster production or lower costs are also considered along with adding another oven.
Meditech is facing issues with on-time delivery of surgical equipment to customers. They are currently delivering products over six weeks late. This is unacceptable in their industry where timely delivery is important. The key causes are a bullwhip effect in the supply chain from poor demand forecasting, long lead times, and frequent new product introductions. Communication issues between departments also contribute to distorted information and panic ordering from distributors.
This document discusses HP's DeskJet printer supply chain in 1990. It describes the manufacturing and distribution process, including production at a facility in Vancouver and shipping to distribution centers in the US, Europe, and Far East. It identifies challenges like forecast errors, long transportation lead times, and meeting demand across different regions. Solutions proposed include making forecasts more accurate using historical data, potentially opening a new factory or distribution center in Europe, and expediting transportation via air to reduce lead times.
7-Eleven uses distribution centers in Japan rather than direct store delivery to consolidate orders from multiple stores. This allows for shorter replenishment times and better tracking of sales data. Receiving products from distribution centers reduces transportation costs for 7-Eleven compared to direct delivery from various suppliers, as distribution centers can consolidate partial loads into full truckloads. This centralized distribution model simplifies ordering and delivery for 7-Eleven's many store locations across Japan.
Barilla, a pasta manufacturer, wants to reduce inventory levels and lead times through a Just-In-Time Delivery (JITD) system with distributors and salespeople. However, distributors want inventory control and independence from Barilla, while salespeople fear reduced responsibilities and bonuses. To address these objectives, the proposal involves piloting JITD with willing distributors to demonstrate benefits. It also proposes making distributors joint owners of sales data or having Barilla representatives monitor inventory. For salespeople, the proposal restructures incentives and redesigns jobs to emphasize inventory reductions and data collection. Barilla would take a long-term partnership approach and help distributors achieve their strategic objectives to build trust.
This document provides an overview of scheduling in production. It discusses what scheduling is, examples of scheduling like timetabling courses and assigning hospital shifts. The objectives of scheduling are to maximize throughput while maintaining balance and priorities. Master production scheduling is introduced as planning completions of end items. The objectives of MPS are to maintain inventories, customer service and due dates. Problems of sequencing jobs like shortest processing time are also covered with an example.
The document provides an overview of simulation modeling. It discusses that simulation is used to mathematically imitate real-world situations in order to study their properties, operating characteristics, and draw conclusions. It outlines the seven steps of simulation as defining a problem, introducing important variables, constructing a simulation model, specifying variable values, conducting the simulation, examining results, and selecting the best course of action. Monte Carlo simulation is described as using random sampling to experiment on probabilistic elements. Two examples of Monte Carlo simulation are provided to analyze inventory management and power generator maintenance costs.
This presentation explains about the Operations Management concept Reorder point, different cases with examples, fixed order interval model, single period model etc.
The document discusses Just-In-Time (JIT), an inventory strategy developed in Japan after World War II. JIT aims to increase efficiency and reduce costs by receiving goods only as needed in the production process, keeping stock levels minimal. Toyota was the first to successfully implement JIT in the 1970s. The key aspects of JIT are receiving stocks just before production and maintaining close supplier relationships, with no production occurring without a customer order. Major benefits of JIT include reduced costs from less tied-up capital and storage space.
This document summarizes a report on Dell presented by Gourav J. It provides an introduction to Dell, outlines its history beginning in 1984, and identifies its current CEO as Michael Dell. The document also describes Dell's vision, mission, direct sales model, supply chain and logistics processes, and concludes that Dell's success stems from its direct sales and build-to-order business model enabled by its use of information technology.
This document discusses inventory management, supply contracts, and risk pooling. It addresses issues like inventory management policies, demand uncertainty, centralized vs decentralized systems, and practical inventory management challenges. It provides an example of calculating optimal order quantity using the economic order quantity model and discusses how demand uncertainty, initial inventory levels, and supply contracts can impact profits. Supply contracts that include a buy-back agreement can increase profits for both manufacturers and distributors by better managing risks from demand uncertainty.
The document discusses the production processes of American Connector Company (ACC) and Denso Corporation's Kawasaki plant. ACC operated 6 plants globally, emphasizing quality and customization which made up 15% of production. The Sunnyvale plant produced 4500 connector models and had undergone expansions. Kawasaki aimed for 99% utilization and customer complaints of less than 1 per million units. It used standardized designs and processes to maximize efficiency and yield. A comparison of ACC and Kawasaki in 1986 and 1991 showed Kawasaki had lower costs due to its lean production approach.
Basic terminologies and EOQ models of Inventory TheoryShashank Naruka
This document provides an overview of inventory theory and economic order quantity (EOQ) models. It defines key inventory terminology like demand, lead time, reorder point, and carrying costs. It then explains the assumptions and calculations for the basic EOQ model, which aims to minimize total inventory costs by balancing ordering and carrying costs. The document also presents a model that accounts for variable demand rates over time. It concludes by listing references for further information on inventory theory and EOQ concepts.
Basic terminologies and EOQ models of Inventory Theory
Stok kontrol yoenetimi
1. STOK KONTROL YÖNETİMİ
1) Stok Yönetiminin Unsurları
)
(Stok yönetiminin önemi, talep ve stok maliyetleri)
2) Stok Kontrol Sistemleri
(Sürekli ve Periyodik Sistemler)
3) Ekonomik Sipariş Miktarı (EOQ) Modelleri
4) Temel EOQ Modeli
(Taşıma, sipariş ve toplam stok maliyeti, EOQ analizi)
KONU 9
Y. Doç. Dr. Fazıl GÖKGÖZ 1
Stok Yönetiminin Unsurları
Stok analizi sayısal yöntemlerin en ilgi gören konularındandır. Bunun en
önemli nedeni ise; her işletmenin belirli bir stok mikyarına sahip olması ve
değeri yönetmek zorunda bulunmasıdır.
İşletmeler, talebi karşılayabilmek ve ileride sorun yaşanmaması amacıyla
önemli olan unsurları stoklamaktadır. Örneğin, bir araba kiralama ofisi
bünyesindeki araçları stoklarken, bir hastane ise tıbbi araç ve ürünleri
stoklamaktadır.
Bunun yanısıra, üretim işletmeleri, hammaddeler ile belirli bir süreçten
geçirerek elde ettiği yarı mamül veya nihai ürünlerini stoklamaktadır.
Konuya talep açısından bakıldığında; talebi ikiye ayırabiliriz
ayırabiliriz.
a)Bağımlı talep : Nihai ürünün üretimindeki ara mamül-madde ihtiyacıdır.
b)Bağımsız talep : İç üretim faaliyetinden bağımsız nihai ürün talebidir.
Y. Doç. Dr. Fazıl GÖKGÖZ 2
1
2. Stok Yönetiminin Unsurları
Stok Maliyeti: Bünyesinde üç çeşit maliyet barındırmakta olup bunlar; taşıma
(carrying) maliyeti, sipariş (ordering) maliyeti ve karşılayamama (shortage)
maliyetidir.
maliyetidir
• Taşıma maliyeti: Mamülü stokta tutmanın işletmeye olan maliyetidir (stokta
tutulması için ısıtma, güvenlik, vb. maliyetler de dahildir).
• Sipariş maliyeti: Azalan / tükenen stoğun tedarikçilerden tekrar sipariş
edilmesine yönelik maliyettir.
• Karşılayamama Maliyeti : Eldeki stoğun yetersiz olması nedeniyle talebin
karşılanamamasından kaynaklanır.
karş lanamamas ndan ka naklan r
Stok yönetiminin en önemli amacı; işletmenin faaliyetleri için gerekli
olan stoğun miktar ve zamanlamasının etkin olarak yapılmasıdır.
Y. Doç. Dr. Fazıl GÖKGÖZ 3
Stok Kontrol Sistemleri
Stok kontrol sistemi sayesinde envanterin ne zaman ve ne miktarda
y
yenileneceği belirlenebilmektedir.
ğ
a)Sürekli Sistem (Sabit sipariş miktarı)
b)Dönemsel Sistem (Sabit zaman aralığı)
Sürekli Sitem : Stok miktarı belirli bir seviyeye düştüğünde gerekli miktarda
sipariş verilir. Siparişin verildiği stok seviyesine yeniden sipariş verme düzeyi
(re-order
(re order point) denilir
denilir.
Periodik Sistem : Belirli zaman aralıklarıyla değişken miktarlarda sipariş
verilmektedir.
Y. Doç. Dr. Fazıl GÖKGÖZ 4
2
3. Ekonomik Sipariş Modelleri
Ekonomik sipariş miktarı (EOQ) modeli, sürekli stok kontrol sistemi
dahilindedir. Sayısal yöntemler bağlamında, bu model toplam stok
maliyetini minimize eden optimal sipariş miktarının t
li ti i i i i d ti l i i ikt tespit edilmesidir.
it dil idi
Temel EOQ Modeli : ekonomik sipariş miktarı modellerinin en basit
halidir. Taşıma ve sipariş maliyetleri toplamını minimize eden optimal
sipariş miktarı yalnızca bir eşitlik yardımıyla belirlenmektedir.
Modeldeki eşitliğin varsayımları;
1) Talep bilinmektedir ve zaman içerisinde sabittir
2) Talebin karşılanamaması söz konusu değildir
3) Siparişin teslimat süresi sabittir
4) Sipariş miktarı tek seferde teslim alınır
Y. Doç. Dr. Fazıl GÖKGÖZ 5
Ekonomik Sipariş Miktarı (EOQ) Modeli
Yandaki grafikte belirli bir Stok
işletmedeki stok siparişinin Seviyesi
döngüsü gösterilmektedir
gösterilmektedir. Talep
Q hızı
Burada,
Q : Sipariş miktarı
L L
R : Yeniden sipariş noktası R
OP : Siparişin alınması
OR : Siparişin teslimi Zaman
OP OR OP OR
L : Teslimat süresi
Q
Ortalama Stok Miktarı =
2
Y. Doç. Dr. Fazıl GÖKGÖZ 6
3
4. Ekonomik Sipariş Miktarı (EOQ) Modeli
Stok
Seviyesi
Genellikle ortalama Stok miktarı
yıllık bazda değerlendirilmektedir
değerlendirilmektedir.
Q
Talep hızı
Stok miktarının “Taşıma Maliyeti”
(Cc) de dikkate alınarak yıllık
taşıma maliyeti bulunur. Q
2
Q
Yıllık Taşıma Maliyeti (TM) = Cc
2
t 2t
Zaman
Y. Doç. Dr. Fazıl GÖKGÖZ 7
Ekonomik Sipariş Miktarı (EOQ) Modeli
Diğer taraftan, gereken stok miktarının
Yıllık
siparişine (Co) yönelik maliyet aşağıda y
Maliyet
verilmiştir.
TC
Eğim = 0
Yıllık Sipariş Maliyeti (SM) = Co D TM
Q
Minimum
Toplam
Toplam Yıllık Maliyet ise; Maliyet
SM
TC = SM + TM
Miktar
TC = Co D + Cc Q Optimal
Q 2 Sipariş, Qopt.
Optimal sipariş miktarı (Qopt.) ; toplam
maliyetin en düşük noktasında
gerçekleşir.
Y. Doç. Dr. Fazıl GÖKGÖZ 8
4
5. Optimal Sipariş Miktarı (Qopt.)
Optimal stok miktarını bulabilmek için TC’nin sıfıra eşitlenmesi gerekir.
TC = Co
D
+ Cc
Q
Q 2
TC = 0
Q optm 2CoD
Co D = Cc .
Qoptm. =
Q 2 Cc
Toplam maliyet, optimal sipariş düzeyinde en düşük değerini alır.
D Q
TCmin. = Co + Cc Optm.
Q Optm. 2
Y. Doç. Dr. Fazıl GÖKGÖZ 9
Optimal Sipariş Miktarı (Qopt.) - Örnek
Örnek:
Halı satışı gerçekleştiren bir firma vitrininde sergilemediği halıları arka planda
bulunan bir depoda stoklamaktadır.
Firma müdürü, optimal sipariş büyüklüğü ile toplam stok maliyetinin ne
olduğunu bilmek istemektedir. Müdür ayrıca, yıllık sipariş döngüsünü de
merak etmektedir.
Veriler şöyledir;
• Tahmini toplam talep : 10,000 m2
• Taşıma maliyeti : 0.75 $
• Sipariş Maliyeti : 150 $ / sefer
Y. Doç. Dr. Fazıl GÖKGÖZ 10
5
6. Optimal Sipariş Miktarı (Qopt.) - Örnek
Cc = 0.75 $
Co = 150 $
D = 10,000 m2 ise;
2CoD
Qoptm. =
Cc
2.(150).(10,000)
Qoptm. =
(0.75)
Qoptm. = 2,000 m2
D Q Optm.
TCmin. = Co + Cc
Q Optm. 2
TCmin. = (150) (10,000/2,000) + (0.75) (2,000/2) = 1,500 $
Yıllık sipariş miktarı = Talep / QOptm. = 10,000 / 2,000 = 5 adet
Sipariş döngüsü zamanı = 311 gün / (D/QOptm.) = 311/5 = 62,2 gün stoklanır
Y. Doç. Dr. Fazıl GÖKGÖZ 11
Zamana Karşı “EOQ” Analizi
Hatırlanırsa, daha önceden EOQ Modelinin sipariş miktarı (Q) ve zamandan (t) bağımsız olduğu
varsayılmıştır. Ancak, bu modeli biraz daha geliştirerek aylık bazda analizler gerçekleştirmek mümkündür.
Bu amaçla yıllık veriler aylık değerlere dönüştürülmelidir
amaçla, dönüştürülmelidir.
Parametre Yıllık Değer Aylık Değer
D (Talep) 10,000 m2 833,3 m2
Cc (Taşıma mlyt) 0.75 m2 0.0625 m2
C0 (Sipariş Mlyt) 150 $ 150 $ (zamandan bağımsızdır)
Dönüştürülen verilen söz konusu EOQ modeli içerisine yerleştirildiği takdirde;
2CoD
Qoptm. =
Cc
2.(150).(833.3)
Qoptm. =
(0.0625)
Qoptm. = 2,000 m2 (Optimal sipariş miktarı değişmemiştir)
Y. Doç. Dr. Fazıl GÖKGÖZ 12
6
7. Zamana Karşı “EOQ” Analizi
Aylık Toplam Stok Maliyeti (TC)
D Q
TCAylık. = Co + Cc Optm.
Q Optm. 2
TCAylık = (150)(833.3/2,000) + (0.0625)(2,000/2) = 125 $/ay
TCYıllık = 125 x 12 = 1 500 $/yıl
1,500
Optimal ekonomik sipariş miktarı gerek aylık ve gerekse yıllık olarak aynı değerde
bulunmuştur.
Y. Doç. Dr. Fazıl GÖKGÖZ 13
Yeniden Sipariş Noktası (R)
Stok
Ekonomik Sipariş Modeli hatırlanacağı
Seviyesi
üzere hangi üründen ne miktarda (Q)
sipariş verilmesi gerektiğini belirlemede
Q
yardımcı olmuştur. Talep hızı
(d)
Artık söz konusu parametrelere ilaveten
siparişin ne zaman yapılması
gerektiğinin de ortaya konulması lazımdır.
R
Siparişin temin süresinden önce
verilmemesi halinde stoklar tükenebilir ve
işletme stok sıkıntısı içerisine düşebilir. Bu
olumsuzluğa meydan verilmemesini
teminen “Temin Süresi” (Lead Time - L)
kullanılarak yeniden sipariş noktası L t L 2t
belirlenir. Zaman
Y. Doç. Dr. Fazıl GÖKGÖZ 14
7
8. Yeniden Sipariş Noktası (R)
EOQ Modelinin temel varsayımları sırasıyla; talebin ve temin süresinin sabit olduğudur.
Buradan hareketle, yeniden sipariş noktası aşağıdaki gibi hesaplanabilir.
R=dL
d = Günlük talep hızı
L = Temin süresi
Örnek: I-75 Halısı satan bir işletme yılda 311 gün açıktır. Halıya olan yıllık talep 10,000 m2
olup, temin süresi 10 gündür. Yeniden sipariş noktasını (R) bulunuz.
R=dL
R = (10,000/311).10 = 321.54 m2 halı
Diğer bir ifadeyle, stok miktarı 321.54 m2 seviyesinde olduğu zaman yeniden siparişte
bulunulması gerekmektedir. Ancak, optimal sipariş miktarı daha önceki slaytlarda gösterildiği
gibi hesaplanacaktır.
Y. Doç. Dr. Fazıl GÖKGÖZ 15
Emniyet Stoğu
Stok
Yeniden sipariş noktasının tespitinde
Seviyesi
talep hızının sabit olarak değiştiği
varsayılmıştır.
Ancak, daha gerçekçi bir bakış açısıyla Q
incelediğimizde talebin anlık olarak
değişimler sergileyebildiği ve
matematiksel anlamda bir doğru
üzerinde hareket etmediği ifade
edilebilir.
R
Yandaki grafikte talebin tam olarak
bilinemediği veya belirsiz olduğu
durumlarda nasıl bir davranış sergilediği
görülmektedir. Zaman
Y. Doç. Dr. Fazıl GÖKGÖZ ? 16
8
9. Emniyet Stoğu
Stok
Seviyesi
Bir önceki grafiğin sağ alt kısmında
karşılanamayan
ş y stok miktarına
karşı;
1) İşletmeci olarak ne yapmalıyız ? Q
2) Nasıl bir önlem almalıyız ? R
Çözüm açıktır;
stok
t k miktarındaki
ikt d ki belirsizlikleri
b li i likl i
dengeleyebilecek miktarda emniyet EMNİYET STOĞU
stoğu bulundurulmalıdır.
Zaman
Y. Doç. Dr. Fazıl GÖKGÖZ 17
İstatistiksel Anlamda Emniyet Stoğu
(Talep değişken-temin süresi sabit)
Daha önceki slaytlarda stok yönetimine ilişkin konular işlenmiş olup, talep ve
temin zamanının sabit olduğu varsayılmıştır.
Peki, gerçek hayata daha yakın bir durum inceleyecek olursak yani talebin
değişken, ancak temin süresinin sabit olduğu durumlarda ne yapılmalıdır?
Emniyet stoğu kavramı tekrar geçerliliğini korumaktadır.
R = d L + Z σd √L
Burada, R = yeniden sipariş noktası
d = Ortalama günlük talep
L = Temin süresi
σd = Günlük talebin standart sapması
Z = Talep yoğunluğuna ilişkin Z-Score değeri
Z σd √L = Emniyet stoğu
Y. Doç. Dr. Fazıl GÖKGÖZ 18
9
10. İstatistiksel Anlamda Emniyet Stoğu
(Talep değişken-temin süresi sabit)
Talebin
temin
süresinde
karşılanma
olasılığı
Stok
bulunmama
olasılığı
Emniyet Stoğu
Z σd √L
Talep
dL R
Y. Doç. Dr. Fazıl GÖKGÖZ 19
İstatistiksel Anlamda Emniyet Stoğu
(Talep değişken-temin süresi sabit)- Örnek
I- 75 Halı satıcısı firmanın karşılaştığı günlük talep
normal d ğ l
l dağılım sergilemekte olup, günlük t l
il kt l ü lük talep h
hızı
30 m2 halı düzeyindedir. Temin süresi 10 gündür. Söz
konusu talebe yönelik standart sapma değeri ise 5 m2
halıdır.
Firmanın %95 güven düzeyinde yeniden sipariş
noktasını ve emniyet stok seviyesini b l
kt i t t k i i i bulunuz.
Veriler:
d = 30 m2/gün, L = 10 gün, σd = 5 m2/gün
Y. Doç. Dr. Fazıl GÖKGÖZ 20
10
11. İstatistiksel Anlamda Emniyet Stoğu
(Talep değişken-temin süresi sabit) - Örnek
R = d L + Z σd √L
R = 30 (10) + (1.65)(5)(√10)
R = 300 + 26.1 = 326.1 m2 halı
Emniyet stoğu ise;
Z σd √L = (1.65)(5)(√10) = 26.1 m2
Y. Doç. Dr. Fazıl GÖKGÖZ 21
İstatistiksel Anlamda Emniyet Stoğu
(Talep sabit-temin süresi değişken)
R = d L + Z d σL
Burada,
R = Yeniden sipariş noktası
d = Sabit günlük talep
L = Ortalama temin süresi
σL = Temin süresinin standart sapması
d σL = Temin süresinde talebin standart sapması
Z d σL = Emniyet stoğu
Y. Doç. Dr. Fazıl GÖKGÖZ 22
11
12. İstatistiksel Anlamda Emniyet Stoğu
(Talep sabit-temin süresi değişken) - Örnek
I- 75 Halı satıcısı firmanın karşılaştığı günlük talep
sabit olup günlük t l
bit l ü lük talep h 30 m2 h l dü
hızı halı düzeyindedir.
i d di
Normal dağılım sergileyen temin süresi ise ortalama
10 gündür. Söz konusu temin süresine yönelik
standart sapma değeri ise 3 gündür.
Firmanın %95 güven düzeyinde yeniden sipariş
noktasını ve emniyet stok seviyesini b l
kt i t t k i i i bulunuz.
Veriler:
d = 30 m2/gün, L = 10 gün, σL = 3 gün
Y. Doç. Dr. Fazıl GÖKGÖZ 23
İstatistiksel Anlamda Emniyet Stoğu
(Talep sabit-temin süresi değişken) - Örnek
R = d L + Z d σL
R = 30 (10) + (1.65)(30)(3)
R = 300 + 148.5 = 448.5 m2 halı
Emniyet stoğu ise;
Z d σL = (1.65)(30)(3) = 148.5 m2
Y. Doç. Dr. Fazıl GÖKGÖZ 24
12
13. İstatistiksel Anlamda Emniyet Stoğu
(Talep ve temin süresi değişken)
2 2 2
R = d L + Z σ d L σ L d
Burada,
R = Yeniden sipariş noktası
d = Ortalama günlük talep
L = Ortalama temin süresi
2
σ d L σ L d
2 2
= Talebin temin süresindeki standart sapması
2
Z 2 2
σ d L σ L d = Emniyet stoğu
Y. Doç. Dr. Fazıl GÖKGÖZ 25
İstatistiksel Anlamda Emniyet Stoğu
(Talep ve temin süresi değişken) - Örnek
I- 75 Halı satıcısı firmanın karşılaştığı değişken günlük
talep hızı
t l h 30 m2 h l dü
halı düzeyindedir. T l b ili ki standart
i d di Talebe ilişkin t d t
sapma 5 m 2 halıdır. Talep gibi normal dağılım sergileyen
temin süresi ise ortalama 10 gündür. Söz konusu temin
süresine yönelik standart sapma değeri ise 3 gündür.
Firmanın %95 güven düzeyinde yeniden sipariş
noktasını ve emniyet stok seviyesini bulunuz.
y y
Veriler:
d = 30 m2/gün, σd = 5 m2/gün, L = 10 gün, σL = 3 gün
Y. Doç. Dr. Fazıl GÖKGÖZ 26
13
14. İstatistiksel Anlamda Emniyet Stoğu
(Talep ve temin süresi değişken) - Örnek
2 2 2
R = d L + Z σ d L σ L d
R = (30)(10) + (1.65) (5)2 (10) (3)2 (30)2
R = 300 + 150.8 = 450.8 gün
Emniyet stoğu = (1.65) (5)2 (10) (3)2 (30)2 = 150.8 m2
Y. Doç. Dr. Fazıl GÖKGÖZ 27
Ödev – 9
Bölüm 1
Bir kitabevi,kullandığı hammade olan kağıdı kendisine yakın mesafede bir
kağıt üretim fabrikasından satın almaktadır. .kitabevinin dergi vekitapları
ğ g p
basabilmesi için yılda 1.215.000 m2 kağıt gereksinimi bulunmaktadır.
Kitabevinin üstlenmek zorunda olduğu maliyetler;
Sipariş maliyeti 1.200 YTL / sipariş
Stokta 1 m2 kağıdı bulundurma maliyeti : 0.08 YTL / yıl
olduğu dikkate alınarak aşağıdaki husuları belirleyiniz ve çözümü
yorumlarınızla (gerekiyorsa grafik çizerek) destekleyiniz.
a) Ekonomik sipariş miktarı
b) Minimum toplam yıllık maliyet
c) Optimal yıllık sipariş sayısı
d) Siparişler arası optimal süre
Y. Doç. Dr. Fazıl GÖKGÖZ 28
14
15. Ödev – 9
Bölüm 2
Bir süpermarket “x” ürününden stoklamaktadır. Söz konusu ürüne
yıllık (365 gün üzerinden) talep miktarı 4.000 kutu düzeyindedir. “x”
x
ürününün sipariş edilmesine yönelik maliyet sipariş bazında 60 YTL
olup, bu ürünün bir yıl süreyle depoda bekletilmesinin maliyeti kutu
başına 0.8 YTL’dir.
Süpermarketi “x” ürününden sipariş verdiğinde dağıtım yapan
firmadan ürünün çekilmesi 4 günlük bir süreyi almaktadır. Bu veriler
ışığında aşağıdaki unsurları hesaplayınız ve gerekli şekilleri çiziniz,
yorumlarınızla destekleyiniz.
a) Optimal sipariş miktarı
b) Minimum toplam yıllık stok maliyeti
c) Yeniden Sipariş noktası
Y. Doç. Dr. Fazıl GÖKGÖZ 29
15