SAP四種安全庫(kù)存的設(shè)置

1、安全庫(kù)存只是一個(gè)籠統(tǒng)的說(shuō)法，本文歸納了SAP四 種安全庫(kù)存(時(shí)間)的設(shè)置，用于增加計(jì)劃過(guò)程中庫(kù)存數(shù)量 (時(shí)間) 的彈性。 為何安全庫(kù)存能增加計(jì)劃的彈性呢因?yàn)樵趦粜枨笥?jì)算( Net Requirements Calculation )中， Quantity available = Fixed receipts + Stock available for planning - Safety stock - requirements ，若可用數(shù)量小于零， 則報(bào)缺料， 視為短缺數(shù)量 ( Shortage quantity )或需求數(shù)量( Net requriements )，將用于批量計(jì)算并得出最終的

2、獲取建議。Safety stockSafety stock partially availableDynamic safety stockSafety time一、Safety stock這就是 安全庫(kù)存”了，安全庫(kù)存的數(shù)量在計(jì)劃中是不可用的。MRP中，若物料的數(shù)量低于安全庫(kù)存水平，就會(huì)產(chǎn)生計(jì)劃訂單。安全庫(kù)存在物料主數(shù)據(jù) MRP2 視圖設(shè)置。二、Safety stock partially available如果設(shè)置了安全庫(kù)存， 一低于該水平就會(huì)產(chǎn)生補(bǔ)貨的請(qǐng)求， 哪怕只是缺了一點(diǎn)， 這增加了計(jì) 劃的工作量。為了彌補(bǔ)這個(gè)不足，我們可以在 MRP Group 中設(shè)置一個(gè)百分比，只有安全庫(kù) 存低于該

3、百分比，補(bǔ)貨請(qǐng)求方會(huì)產(chǎn)生。三、Dynamic safety stock動(dòng)態(tài)安全庫(kù)存就更加厲害了，它根據(jù)平均的日需求( Average daily requirements )數(shù)量，來(lái) 確定未來(lái)幾個(gè)時(shí)期的安全庫(kù)存水平(數(shù)量等于若干個(gè)平均日需求)：最小庫(kù)存、目標(biāo)庫(kù)存、最大庫(kù)存。若小于最小庫(kù)存，產(chǎn)生補(bǔ)貨請(qǐng)求至目標(biāo)庫(kù)存；若大于最大庫(kù)存，系統(tǒng)將提示例外信息。若同時(shí)設(shè)置了安全庫(kù)存，將累加。該配置稱為 Range of Coverage Profile，在MRP2 視圖分配，配置在 IMG: Production - MRP - Planning - MRP Calculation - Define Ran

4、ge of Coverage Profile (Dynamic Safety Stock)。四、Safety time前面三種方案都是對(duì)安全庫(kù)存數(shù)量上的設(shè)置， Safety time 則是設(shè)置時(shí)間上的余量。 物料的補(bǔ) 貨提議時(shí)間將提前于實(shí)際的需求時(shí)間，提前日期在MRP2視圖中配置?？紤]到物料可能用在產(chǎn)品的不同層次，為了避免重復(fù)提前，可以在 MRP2視圖的Safety time indicator欄位設(shè)置安全時(shí)間有效于所有需求還是僅相關(guān)需求， 或者干脆無(wú)效。 而考慮到不同時(shí)期對(duì)安全時(shí)間的 長(zhǎng)度要求不同，可以在后臺(tái)定義 Period Profile， IMG: Production - MRP -

5、 Planning - MRP Calculation - Define Period Profile for Safety Time/Actual Range of Coverage ，并在 MRP2 視圖分 配給物料。注意： 百分比是根據(jù) MPR組設(shè)置的，在后臺(tái)：Define Safety Stock Availability。從我的測(cè)試結(jié)果來(lái)看，系統(tǒng)計(jì)算的順序是：Safety Stock實(shí)際需求Dynamic SafetyStock，然后提前Safety Time的時(shí)間來(lái)產(chǎn)生相應(yīng)采購(gòu)申請(qǐng)Dynamic Safety stock:The dynamic safety stock is ca

6、lculated in the planning run of the order proposal quantity. In the MRP evaluation, MD04 - you can check the parameters used to calculate the dynamic safety stock in the period totals set the dynamic safety stock themaster data settingsrequired are, 動(dòng)態(tài)安全庫(kù)存是運(yùn)行于預(yù)測(cè)需求的計(jì)劃。 當(dāng)運(yùn)行 MD04 時(shí)，你可以在區(qū)間統(tǒng)計(jì)界面看到所有 的用于計(jì)算

7、動(dòng)態(tài)安全庫(kù)存的參數(shù)。你要設(shè)定以下參數(shù)才能計(jì)算出動(dòng)態(tài)安全庫(kù)存1. Maintain MRP view.2.1. 維護(hù)材料主檔的 MRP 視圖2.3.In MRP 2 view enter the coverage profile which in configuration will carry the elementsrequired as detailed below.3.在 MRP2 視圖里，需要設(shè)定覆蓋組件( coverage profile )4.Material master- you have MRP type PD.4. 設(shè)定的 MRP 類型為 PD。It is maintain

8、ed in SPRO under the node-> 覆蓋組件在后臺(tái)配置，路徑如下SPRO -Production-Material Requirements Planning-Planning-MRP Calculation-Define Range of Coverage Profile (Dynamic Safety Stock).It is maintained with respect to a plant as the calculation is plant specific.Calculation-The dynamic safety stock is calculat

9、ed using the following formula: average daily requirements * range of coverage因?yàn)橛?jì)算是基于工廠的，所以配置也是在工廠的基礎(chǔ)上進(jìn)行的。 動(dòng)態(tài)安全庫(kù)存的計(jì)算公式如下：動(dòng)態(tài)安全庫(kù)存 =每日平均需求 * 覆蓋的區(qū)間The individual parameters are described below: 下面是各個(gè)參數(shù)的解釋Average daily requirements每日平均需求The calculation of the average daily requirements is carried out usi

10、ng the following formula: requirements in the specified periods/number of days in the total period length 。 You must maintain the following parameters for the calculation of the average daily requirements: 每日平均需求的計(jì)算公式如下：每日平均需求 =特定區(qū)間內(nèi)的總需求 / 此區(qū)間內(nèi)的天數(shù) (天數(shù)有不同的計(jì)算方法，下面有比較詳細(xì)的介紹。 ) 下面的一些參數(shù)是在計(jì)算每日平均需求中必須的1. Pe

11、riod indicator區(qū)間指針You use this indicator to determine the calendar period for which you want to carry out the average daily requirements.這一指針用于決定計(jì)算每日平均需求的日歷區(qū)間Here you can enter the following: 有如下幾種設(shè)定 weeks (W) 周 months (M) 月periods according to the planned calendar (K) 根據(jù)計(jì)劃日歷決定2. Type of period leng

12、th區(qū)間天數(shù)的計(jì)算方法You use this indicator to determine the length of the individual periods in detail. 用于決定計(jì)算區(qū)間天數(shù)的方法Here you can enter the following: 如下幾種設(shè)定可以用作計(jì)算 workdays 工作日 calendar days 日歷日 standard days 標(biāo)準(zhǔn)日If you set standard days as the period length, you must enter the number of days per period in th

13、e "NO. standard days" field.如果設(shè)定了標(biāo)準(zhǔn)日作為區(qū)間天數(shù)，必須要設(shè)定每個(gè)區(qū)間包含多少標(biāo)準(zhǔn)日。3. Number of periods 區(qū)間數(shù)Here, you define the number of periods you use to calculate the average daily requirements. 在這里要設(shè)定用于計(jì)算每日平均需求的區(qū)間數(shù)。Determining the range of coverage 定義覆蓋區(qū)間You can determine the range of coverage for a maximum

14、 of three periods and you can maintain different coverage for each period.To do this, you must define the ranges of coverage and the periods in the screen section entitled, "Determine range of coverage".可以為三個(gè)時(shí)間范圍設(shè)置不同的覆蓋區(qū)間Determrie range of coveragePeriod incficatorW WwekDetermine average r

15、equirementsNumber of periodsI Type of perergth1）No. oF Days per Period0Range of 匚overage in the first periodMm,30Tgt3 口Max, 33Number of Periods52Range of coverafle in the second periwi0Number of Periods0Min.o-Tgt0Max.Range of ccwerage in ths rest of tl>e borizonMir. 0 Tgt 0 Max. DYou also have th

16、e option of limiting the range of coverage in each of the three periods by en teri ng a minimum and a maximum range of coverage. The system checks whether the actual range of coverage （ available quantity / average daily requirements） lies below the minimum range of coverage or above the maximum ran

17、ge of coverage. If this is the case, the dynamic safety stock level is recalculated using the in formatio n for the target range of coverage.也可以為不同的時(shí)間范圍設(shè)置覆蓋區(qū)間的范圍。填入最小和最大區(qū)間即可。系統(tǒng)會(huì)檢查實(shí)際覆蓋區(qū)間（可用數(shù)量/每日平均需求）是否小于最小或大于最大。如果是這樣的，動(dòng)態(tài)安全 庫(kù)存會(huì)用目標(biāo)區(qū)間來(lái)重新計(jì)算。以下有兩個(gè)例子：Example -1例一Coverage profile - 001, with followi ng sett

18、 ings assig n in material master - MRP2 view,Period type = M （月）No of period =2（區(qū)間數(shù)）Type of length = 3（標(biāo)準(zhǔn)日）and days/period = 20（每個(gè)區(qū)間包含 20個(gè)標(biāo)準(zhǔn)日）.Range of coverage for first period （target） = 3 （目標(biāo)覆蓋區(qū)間 ）,no of periods= 2（區(qū)間數(shù)）Lets us say requirements areas below -需求如下-1000-2000No of days = 2*20 = 40 （天數(shù)

19、）average Daily requirement = （1000+2000）/ 40 = 3000/40 = 75 （每日平均需求）Safety stock requirement = 75*3（target） = 225.（動(dòng)態(tài)安全庫(kù)存）Run MRP result is as below運(yùn)行MRP,結(jié)果如下- pl order qty- 1225 available qty - 1225- VSF 1000- available qty - 225- pl order qty - 2000 balance - 2225- VSF 2000- available qty - 225.Ex

20、ample - 2 例二Coverage profile - 002, with following settings, assign in material master - MRP2 view Period = M（ 月）No of period = 1 （ 區(qū)間數(shù) ）Type period= 1 （工作日 ） . working days as per factory calendar, please check your factory calendar. it is taking form no of days of factory calendar, remove the days which already passed, then remove holidays. （根據(jù)工廠日歷計(jì)算。從總天數(shù)中減去已過(guò)的天數(shù)和假日） Example - In factory calendar - 工作日舉例2,3,9,10,16,17,23,24,30 are holiday. i,e 9 days in 30 days are holidays, 2,3,9,10,16,17,23,24,30 是