Logistik Flashcards

Question

What re the different pull system?

Answer 1

* one card kanban * two card kanban * kanban square * two bin systsems * CONWIP ( constant work in process Kanban boards can be used. can tell when to start to produce

Answer 2

1. start with "2" boxes at both supplying and receving stations 2. At the reciving station when a box is picked the vard is moved away and put in a card box. A truck driver picks the box and moves the card to the supplying station. 3. The card initate production at the supplying station. The truck driver takes a box with the material from the supplying to the receving station and takes the empty boxes from the reciving to the suppling station. 4. The supplying station fills the empty box

Answer 3

station 1 supplies station 2 1. Operator at station 2 takes part from one bin and removes the card. The transport card is put in the collection box. a transport picks the card abd sends it to station 1 (signal for transport) 2. The operator at station 1 takes the production card (signal to produce) from a full box and attaches the transport card to the box. 3. The box with the transport card is sent to station 2. and empty boxes at station 2 is sent to station 1 4. when one or a number of production card have been gathered at station 1, the production stats. 5. at each filles box, a production card is placed which will indicate production of those parts

Answer 4

Move kanban: * itam number * card no e.g 3 of 5 * consuming unit * container cpacity * supplying unit Production kanban: * item number * card no * raw material * min. number of card to start production * container capacity * supplying unit * tools needed

Answer 5

* A work center should withdraw only item which it requires from preceding work center in the quantities required and, equally importantly, at the required time * A wokr center or process should only produce those items which have been removed by the following work center or process * defective or substandard items should never be passed to a following work center * the number of kanban should be miimized * the kanban system is only suitable for dealing with realtively small fluctuations in the demand pattterna in the final assembly line.

Answer 6

* orders sent-from the last process to the first * genreric signal- what to produce is based on a dispatch list benefits: * can handle more complex environments than kanban * allows for mix variations over time

Answer 7

We move from the current to a future state with help of contnous improvements! so: a improvement is only something that does that we get closer to the future state? * understand the current state * deterine next future state * identify obsticles on the way to the future state * use the PDCA-method to step by step to the future state * how do we know the future state? measure?

Answer 8

* To release orders at the rate that capacity conditions will allow them to be executed with reasonable throughput times. * To ensure that start-up material are available when each order is planned to start * To ensure that orders realsed to manufacturing in the workshop are completed in a suitable sequence with respect to delivery precision Starts with tha manufacturing order that goes to: order realse control material availaibility check Genration shop package Then it goes to priority control that goes to labour control and final reporting

Answer 9

Determining which manufacturing orders should be relesed to the workshop to consider: * available cpacity * materials requirements Methods: * Order relase from planned start times * Regulate order release * Input/output control

Answer 10

Start times are based on material requirement, order relased without consideration to capacity -\> i.e not good if high variation Characteristics: * Simple to apply, requires little resources * start and due times represent actual demand points -\> basis for prioriting in the workshop * capacity no considered -\> uneven workload -\> varying throughput times Primary environments: * Smooth workload * stable demand * Large capcity in relation to production volumes or high volume flexibility * short throughput times and small order quantitites

Answer 11

Order sheduling considers capacity Characteristics: * More complex and time consuming -\> requires advanced system support * Results in smoother workload -\> stable throughput times and fewer queuing problems * important to keep capacity requirments apdated Rimary environments: * Uneven capacity requirements * long throughput times * products with simple bills of material and few operations

Answer 12

Controlling input, output and queue, control the sheduleorders against cpacity requirement from allready released and available cpacity. characteristcs: * simpler thn the regulated order relase * ... but still provides a smoothing workload and throurghput times * start and due times represent actual demand points -\> basis for prioriting in the workshop Primary environments: * manufacturing cells and line processes, or job shop with short throughout times

Answer 13

checking material availability before order relase to avoid material shortage Methods: * physical allocations: * manual check and moce to shopfloor stock * Administrative avaialability check: * Accounted stock on hand * acocunted avilable stock on hand important to keep track of inventory levels

Answer 14

e.g: * order identity * tools required * routings * materials required

Answer 15

characteristcs: * simple to use and has a positive effect on the motivation of the workhop personnel * often focus in factors like setup times and throughput * less focus in material requirement Primary environment: * small workshop that are easy to overview Priority rules: * first in, first out: orders with the eraliset arrival time are also processed first. * Shortest operation time rule: orders with short operation times are given priority * Highest number of remaining operations first: orders with many operations are given priority. * Largest order value first: orders with high order value are given priority * sceduling based priority rules: e.g. earliest finished time first Priority based on dispatch list: * carried out centrally and communicated through printouts or terminals * chould be based on priority rules * chould also be based on more advanced logic, considering e.g. finite cpacity planning

Answer 16

purpose: * following up on realesed orders, handling potential deviations compared to plan * updating resource avaialability, for example materials * supplying information on real resource consumption, to match against what had been planned

Answer 17

defjnition of constraint: A constraint is anything that limits a firms performance. basically there are two types of constrains; resource constraints and market constraints. 1. identify the system constraints 2. Decide hos to exploit the systems constraints 3. subordinate everything else 4. elevae the systems constraints 5. if a constraint has been eleiminated, go back to step 1

Answer 18

drum: the constraints is the drum and the production rate is the drupbeat buffer: an inbound buffer is palced before the bottleneck, so that it is never starved. Rope: the signals that control the flow are the rope. e.g kanban varying batch sizes: * batch sizes often not the same throughput the processes * larger batches desirable in the bottlenecks * process batch size vs operation batch size vs transfer betch size mindset and culture: * non-bottlenck resources not critical- may remain idle * understanding and acceptance important * similarities to pull system

Answer 19

* little adminastration * suitable mainly for low- value materials

Answer 20

in the top is the headline: compomet inventory / WIP/ finished goods inventory on the left side is the consumed/arrivals and on the right is the withdrawals

Answer 21

A methof of inventory bookkeeping where the book inventory of componets is automatically reduced by the computer after completion of actiity on the componets upper-level parent item based on what should have been used as a specified on the bill of material and allocation records. * can not be used when kanban methods is used * is good when lead times is short * needs correct BOM WIP rapporteras inte syncroflushing at operations: updating componets invertory when reporting finsihed operatiosn using shop floor stock: delivery to stock from min warehouse

Answer 22

* line stocking/ continous supply * batching * seqeuncing * kitting (stationary) * Kitting (trevelling)

Answer 23

* infront of the operator: for small products and parts * behind the operator: for large products

Answer 24

* forklifts, for big unit loads * tuggers and trains of tow carts: "milk run" * automated guided vecicles = AGV

Answer 25

takes different ampunt of time depending on how much materials that is left. the containers can be tilt to avoid this problem and decrease the avrage time with 45%

Answer 26

* potential conflict between efficency in-plant matertials supply and effeicency of assembly * smaller unit loads require more frequent deliveries. * principally different ways of delivering: * large unit loads often delivered by forlifts * small unit loads can be delivered by tugger trains using a "mild run" approch

Answer 27

* parts picked from part number specific containers, filling each kit with the right parts for the respective assembly object. * kit preperation can be preformed in a warehouse or in a smaller designed kit preperation area * Kits can be prepared either one at a time or in batches

Answer 28

* space saving at the assembly stations * ... but increased overall space requirement * Reduced man hour consumption of the assemblers * ... but increased overall man hour consumption in the plant * improved flexibility. espacially with travelling kits * Increased support to the assemblers, espacially with kits with formal structure * ... but certain difficulties achieving high quality kits advantages: mainly on the assembly station) * space * man hour consumption, throughout time * improved flexibility, different variants and rebalancing * improved quality, assuming correct kit content drawbacks: (mainly in the material supply) * space * man hour consumption * quality assurance- picking the right parts

Answer 29

* paper list * pick-by-light * pick-by-voice * pick-by-vision

Answer 30

* S&OP planning: * level of aggregation: product group * Topmanagement involvement: when reconciling functional plans * Forcast horizon: 1-2 years * forast frequency: monthly or quartely * Master production scheduling: * level of aggregation: product * Topmanagemeanf involvement: very little * forcast horizon: months- up to a year * forcast frequency: weekly or monthly

Answer 31

* demand uncertainty can result from the increasin rat of change in the market * Can result from behaviour in the suppy chain, making demand fluctuations increase upstream (bull-whip effect) The forcast = not budget, not whishes, not what we hapened to produce/ sell last period, not what we think we van manage ..... but "the unconstrained demand"

Answer 32

* forcast data * the length of the forcast period- e.g. week, month, year? * demand more even for longer * forcast frequency- how often we rewiev forecast? * Forcast horizon- how many periods ahead we are looking? * aggregation level- product, product group? * demand more even group * forcast units- pieces, meters, liters, kilogram, monetary unit, etc?

Answer 33

* random * trend * seasonal * can also be combined, random is always present

Answer 34

Qualitative: * based on subjective judgement * based on few formal calculations advantages: * up - to-date knowleadge of changes and elements occurring in the environment that affect the forcast disadvantages: * short them memory, overconfidence bias (wishful thinking more than realistic assessments) Quantitative: * based on calculations (more or less advanced) advantages: * objective, consistent, capable of processing large amount of data disadvantages: * only as good as the sata upon which they are based, when changes occur in the data that are not incoporated in the model the forecast cannot be accurate

Answer 35

sales management method: * management personnel gather in meeting(s) to forecast deamnd * considerations to sales statistics * forcast breakdown into regions * quick way to produce forecast * consensus achieved among (participating) manangement * risk of subjective assessments, managemnt decides-rather than the idividuals closet to the market Grass root method: * initial assessments made by sales people and other personnel indirect contact with the market * The initial forecast are collected and processed centrally * a common forecast is created for the whole company * forecast produced by those with the most knowleadge of the market * responsibility ro realise forecasts falls upon those who made them * forcast breakdown into regions not neccessary * takes more time than the sales manangement approch * risk of subjective assessments Pyramid forcasting: * both management and grass root participation * bottom up- top down * if the grassroot forecast from the management forcast, grassroot forcast are propotionally adjusted * the original proportion between e.g. regions or product areas remain * the total equals manangement total * sales staff not ties to its own forecasts

Answer 36

* moving average: * number of moving average: the choice of the number of periods (n) is decisive for how the method will operate. * if a large value of n i chosen, forcast is table to random varaitions in demand, but reacts slowly to systematic changes in deamnd, so if random more n than if trens * expontial smoothing: * choice of alpha: * large alpha, responsivness to systematic change in demand, e.g small n * small alpha, stability to random varaition, * stable trend mid to large beta * Focus forcasting: * simple logic of it workes before, it will probably work again * For every forcast occation tests are made by running simulations to find which method that would have worked best in the previous periods, where the autscome is known * The best working method is selcted to gereate the forecast for the next period * assumnes access to large computer cpacity

Answer 37

additive trend: D(i+1)-D(i) Seasonal index: D(i)/D(m) D(m) = average demand

Answer 38

* Important to supplement forecast methods with different types of forcast monitoring to avoid suprises * estimate forcast error * check the forcast remains within acceptable margins of error

Answer 39

* Products are manufactured without requiring any customer orders * prologes delivery lead time e.g. increase of shorttages in stock order backlog * two types of orders: "traditional " orders and call-offs * available- to- promise (ATP). basis for providing information about delivery lead time. * order registration (manually or electronically) * picking and delivery * alocations removed and quantities updated

Answer 40

* available-to- promise is the quantity of and items that sales can promise to deliver in specified planning periods without affecting other customers deliveries. generally preformed by the ERP system. * calculated in the first period and in periods with scheduled receipts * ATP = scheduled receipts during the period - allocations prior to the next inbound delivery

Answer 41

* Make-to-delivery-schedule: manufacturing takes place according to a predetermines schedule, in line with an overall agreement. * call-offs made to initiate delivery * quantities manufactured either directly or to stock

Answer 42

* Final product unknown before the customer order is received * since assembly/ final manufacturing does not take place until te customer order is received there will be a delivery lead time * customer specifies exactly which variant that is desired * to manufacture the product variant a manufacturing order must be created * determining possible delivery dates to customer order, two options: * fixed delivery lead time (generally set based on experience) * Available to promice calculations * Focus on capacity for assembling products * in addition, calculations need to be made for madules included in the products * same approch as for make- to- stock companies described

Answer 43

* Final product unknown, semi-finished products and purshased products unknown to some extent * products must be specifies before an order can be prepared * available to promise calculations must consider both access to material and access to capacity

Answer 44

Aim: * To achieve a balance between supply and demand in such a way that a companys efficiency and competitveness are promoted * To intergration organizational functions in the process and create consensus among one set of goals and plans * actual contract may be written Input to s&op: * Market and customer data, to anticipate the future demand * a forcast of aggregate deamdn convering the selected planning horizon (often 12-24 months) * The current status of the system in terms of worforce level, inventory level, production rate, supplier capabilities, etc. * the options available to adjust cpacity * the options available to adjust demand Output: * A sales plan, a delivery plan, and a production plan: desisions for each planning period within the planning horizon about issues like: * workforce and capacity levels, intventory level, or customer leads tie and order backlogs, production rate * Projected costs and cashflows if the production plan eas implemented i.e. economic evalution * " one set of numbers" Design parameters: * planning object; what does production an delvery plan refer to (product, product group) * capacity unit : which level considr capacitym workshops, lines * planning horizon * refquency

Answer 45

* Budgeting -\> budget, i.e. a financial statement * S&OP -\> long-term plan for sales and production * the sales and operations plan chould be constrained by the budget and may also be an important input to the budgeting process.

Answer 46

1. Forecast future demand 1. forcast- often from marketing/ sales department; expected demand in coming period. 2. should be as a relastic and accurate as possible 3. Does not consider potential capacity restictions 2. prepare preliminary delivery plan 1. comapre previous delivery plan with volumes actually delivered 2. adjustments can be made compared to the forcast 1. plan to deliver less e.g. to phase out product 2. Plan to deliver more, by use of e.g. price reductions or marketing campaignes 3. Establish goals for finishes goods inventory or order backlog 3. Prepare preliminary production plan 1. Compare previous production plan with volumes actually produed 2. takes the preliminary delivery plan as a point of depature 3. considers the balance between delivered volumesm produced volumes, and inventory/backlog 4. consider available capacity and start up materials 4. Adjust delivery plan and production plan 1. meeting including representatives from: 1. marketing(sales, operations and finiance 2. make adjustments: 1. delivery plan, production plan, inventory levels/backlog 5. Establish delivery plan and production plan 1. Delivery plan and production plan are put forward to top management 2. Signifies an agreemant within the comapny: 1. marketing department undertakes to sell agreed volumes 2. production and purchasing undertake to produce agreed volumes.

Answer 47

* Pla nthe defines the specific goods that specific shops will produce in definite quantities at definite times over a short term horizon compared to s&op, in accodrance with the aggregate plan (from S&op) * Typically stated in produc specification terms (end product numbers) * The basis for promising deliveries to customers * available-to-promise, ATP * The master production schedule does not present an executable manufacturing plan-further details are needed Planning horizon: * A long horizon is associated with uncertainties * How long horizon is actually needed * The horizon applied must be "long enough" * Sufficient for budgeting * seasonal variations and busniess outlook * Time to adapt capacity * Accumulated product lead-time Design parameters: * Planning object * the capacity unit * planning horizon, shortest pllaning horizon = cummulative production lead time * frequency

Answer 48

* The planning use of the aggregate production plan from S&OP is to balance the production schedule so that the production costs are minimized, given a certain service level, and to assure capacity being available for this * However the output of an aggregate plan does generally not indicate individual products. This means that for more details planningm the aggregated plan must be disaggregated into individual products. The result of such a disaggregation is what is known as the result of such a disaggregation is what is known as the master production schedule. * Can be done at the same time * More calculations in MPS.

Answer 49

* Release time fence: time in advance in within manufacturing orders are released * Demand time fence: Normally applied lead time to customers. No order normally received within the demand time fence. * Planning time fence: Distinction between planned rders and firm planned orders * Forcast time fence: The point in time beyond which order backlog is negligible to forecast

Answer 50

Layout: week/period, forcast,orders, inventory, MPS, ATP, cummulative ATP Runda alltid uppåt på antal produkter Inventory current period = inventory previous period + MPS - Orders Before the demand fence only consider orders. otherwise consider the biggest one. ATP = MPS for the period- order until period with next MPS.

Answer 51

Independent demand: * For an iteam that has no direct relation to any other itam * Itam sold as end product or e.g. spare parts. Dependent demand: * Can be traced to the demand for another item * e.g. componets that are to be assembled into an end product

Answer 52

* Re.order point system * Run-out time planning * Periodic ordering system * Material requiremants planning (MRP)

Answer 53

Re order point= safetystock + demand\* lead time appropriate environments: * Independent demand (mainly) * Finished goods stock * Even and predictable demand * Low value iteam such as screws * small order sizes and short lead times * Access to capacity not a major problem

Answer 54

* Run-out time is also called cover time planning * Realted to re orcer point system , but calculates time instead of quantity: Run out time = stock on hand/ deamnd per period * To safe guard against uncertainty and variation in demand during replenishment lead time, safety lead time is used * Rule: if run out time \< (replenishment lead time + safety lead time) -\> order

Answer 55

* Planned deliveries with fixed interval and varying order quantities * need to decide appropriate order quantity * to do so one uses the target level: in formel samling * The ordering quantity is then chosen as the order up to level minus the safety stock: i formel samling Appropriate environments: * Independent demand (mainly) * finished goods stock * Frequent and continous demand * small order sizes and short lead times * access to capacity not a major problem * coordination of items

Answer 56

calculations based on: Master production scedule data, bill of material data, inventory data Pegging: * Shows the parents creating the demand for somponets, the quantities needed, and when * Uses "where-used" logic to identify current of demand * may be single- level or full level Appropriate environments; * Dependent demand, e.g. raw amterial and compoents * Independent demand- espacially with seasonal variations * high basic data quality; e.g. billf of material, stock on hand and lead time Constraint based MRP: * Traditional MRP does not consider capacity * advanced system support can be utlized to consider capacity cosntraints: advanced planning and sceduling (APS): * sets additional deamnds fro quality of basic data: routing and work centre data * change of plans if capacity i identified as a constraint Layout: Week/period, part need from X etc, total gross requirement, scheduled receipts projected available balance (ingående balans) Planned order recipt planned order start

Answer 57

* In a strict kanban system, orders are intiated based on requirements from downstream processes instead of from the order planning function * In practice, pull control are can be combined with central plan so that orders are realsed based on plan, but controlled on the shop floor by use of generic kanbans- or CONWIP

Answer 58

alla can be categorized in fixed and varaible: fixed = same quantity is order every time but with different interval variable= different quantity is order bur with the same interval * Fixed lotsize varaible run out time: * Estimated order quantity * economic order quantity EOQ * Variable lot size and fixed ron out time: * Lot of lot * Estimated run-out time * economic runt-out time ERT * Varaible lotsize and varaible run out time: * Dynamic lot sizing methods: silvermeals method

Answer 59

* The order quantity matches the consumption for each period * can be used in make-to-order context or when ordering costs are low

Answer 60

Based on experience ? * Decides a fixed quantity and let order frequency vary * Practical restictions can make estimated order quantities suitable: e.g. procurement in large package or restictions in storage space available

Answer 61

Based on experience * Similar to estimated order quantity * based on experence.. but decides a fixed order frequency and lets order quantities vary

Answer 62

EOQ, lotsize with minimized cost Find the suitable trade off between odering cost and inventory. formel i formalsamling

Answer 63

* Average order quantites equal to the EOQ * .. but ordering quantity variable and order interval constant * ERT = EOQ /D

Answer 64

* Variability in demand during lead time * Uncertainty in stock on hand * Length of the lead time * Variability of the lead time * frequency of ordering * desired customer service/shortage costs

Answer 65

* Manual estimation based on experience * percentage of lead time deamnd * Proportion of no shortage during order cycle, based on cycle duration * Proportion of demadn fulfilled directly from stock, based on fill rate service definition

Answer 66

Different measures of service level cycle service: the proparbility that no shortages occur in a inventory cycle

Answer 67

# Fill rate service: The proparbility that a customer does not have to wait. proportion of demand that can be fulfilles directly from stock.

Answer 68

* Iteratice proces * start in week one , how many weeks demand should it cover? * if one week included = s(ordering cost) * ..two.. = S+ D(2)\*invcost\*weeks stored(1) * ..thrre = S+ D(2)\*invcost\*weeksstored(2)+ D(3)\*inv cost\*weeksstored(1) * Try till cost increses selec loest e.g. three weeks demand * Then start again from week 3 how many weeks deamns should be included.

Answer 69

Lead strategy: * Capacity changes precede demand changes- also in case of decreasig demand, proactive Lag strategy: * Capacity changes precede demand changes- also in case of decreasing demand: reactive Level production strategy: advantages: * smooth, level production avoids labour costs of demand matching * are there "sweet sports" regarding production rate * smooth demand on upstream operations Disadvantages: * Build-up of inventory * can we aford producing "in advance"- cash flow * Other resources being barriers? * Requires accurate forecast * risk of absolute inventory Chase strategy: Advatnages: * stable inventory disadvatanges: * costs of hiringm training, overtime, extra shift etc. * costs of layouffs and impact on employees * possible unavailability of needed work skills, supplier capacity etc. * maximum capacity needed

Answer 70

* Capacity planning with overall factors * Capacity planning using capcity bills * capacity requirements planning (CRP)

Answer 71

* uses the same unit for expressing capacity requirements as used in the production plan (e.g. units of finished products) * Capacity planning is carried out for each product * simple way of planning capacity Characteristics: + need for little data + simple calculations - affected by changes in product mix - no lead time off-setting Appropriate environments: * simulation capabilities desired * short accumulated time * S&OP and MPS

Answer 72

Multiplying capacity needed for each part of the product with the number of products planned in MPS and summed them up for all products Characteristics: + Realtiviely simple and easy to understand + link between end item and resources needed + can handle product mix changes - requires data about product structure and operation times - does not consider setup times other than a general manner- i.e. in practice assuming constant order quantities - no lead time off-setting Appropriate environments: * S & OP and MPS * Sumulation capabilities desirable * Short set up times and small order quantities

Answer 73

* required capacity is calculated from the point of operations associated with relesed and planned production orders * MRP is usually used to generate info about manufacturingorders * basic data used for each item. e.g. routing, set-up times, operation times * capacity requirement are calculated individually from the production of each of the incoporated items seperately Desitrbution of operating time: capacity requirementscan be distributed in two ways: 1. alla capacity requirements places in the period with the finish time for the operation 2. capcity requirements proportionally allocated between the planning periods where the operationnwill e going on. Characteristics: * Requires details product, inventory, routing and work centre planning data * Requires standard items with known planning data * Gives very detaild plans 8e.g. for single work stations or machines) * Seperates load from planned and sceduled orders. * consider the projected available inventory * Mangers long lead times and varying order sizes Appropriate environments: * High capacity planning accuracy desired * order planning and execution and control

Answer 74

Overload: * Use overtime, extra shifts * transfer personnel * hire more help * split lots and spread out production * use alternate work centers * install more equipment * offer incentives to customers Underload: * Use time for traning and maintenance * transfer workers * use temporary layoffs * shorten workdays, weeks * reduce subcontractors

Answer 75

Possibilities for re-allocatiing capacity requirements Alegbraiccally: processing B2 at OP1 + transport B2 to OP2 = Transport B1 to OP2 + setup OP2 + processing B1 aat OP2 Time saved is: ST2 + Processing B2 in OP2

Answer 76

A techique for calculation operation start dates and due dates. the scedule is computed starting with the due date for the order and working backward to determine the required start date and(or due dates for each operation

Logistik Flashcards

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