Monday, October 1, 2012

SNP and PPDS difference

You use Supply Network Planning (SNP) to create a feasible, medium to long-term production and distribution plan for critical products (products with long replenishment lead times or products that are produced on bottleneck resources). This plan should ensure that the required product quantities in your supply chain are available at the right place, at the right time, without overloading bottleneck resources for production and transportation. A key task of SNP involves determining the optimum sources of supply. Based on cost aspects, SNP decides where, when, and in which quantities products should be procured, produced, or transported in the supply chain. SNP plans according to periods and quantity. Order dates are exact to the day and detailed order sequences are not considered.

You use Production Planning and Detailed Scheduling (PP/DS) for detailed production planning; that is, for planning the lot sizes to be procured, for planning order dates to the second, and for planning order sequences on the production resources. Accordingly, in PP/DS you plan in-house production based on detailed, complete BOM (production process model plans, iPPE process structures, or PP/DS runtime objects) and on resources with a time-continuous capacity

For SNP planning, on the other hand, you use rough production process model plans (PPM plans). These contain only a section of the BOM with the critical components. You use resources with a period-related capacity, where the smallest period is a day

You separate the responsibilities for planning using the PP/DS horizon and the SNP production horizon. Planning within the PP/DS horizon is part of PP/DS planning and planning outside of the SNP production horizon is part of SNP planning, although the planning areas may also overlap. If, within short-term planning, you want to execute more detailed planning on receipts created by SNP, meaning that you want to plan them with detailed dates and a complete BOM, you must convert the SNP receipts into PP/DS receipts If the SNP receipts reach the PP/DS horizon, you convert the SNP receipts into PP/DS receipts.

SNP planning results primarily in stock transport orders. These orders are relevant to PP/DS if the stock transfer requirements concern production plants. 

SNP alone plans receipts and determines cost-effective sources of supply and lot sizes. You only use PP/DS to plan the receipts created by SNP in detail (that is, to complete the BOM) and to execute sequencing (for example, with setup time optimization). PP/DS copies the SNP source of supply decisions during conversion.

If you want the PP/DS horizon and the SNP planning period to always follow each other without a gap, you only enter the SNP production horizon in the location product master, and no PP/DS horizon. The system automatically uses the SNP production horizon as the PP/DS horizon. This is required in particular if you define the SNP production horizon in calendar weeks or calendar months. 

If you want to consider the resource loads caused by PP/DS orders in SNP planning, and adjust the SNP planning accordingly, you must use mixed resources (single-mixed resources or multimixed resources) 

Source of Supply
Use a PP/DS PPM, for which you have defined a lot size interval, to create a corresponding SNP PPM with the same lot-size interval.
 Use a PP/DS PPM, which allows operations to be processed in different modes, to create an SNP PPM for each possible mode combination.
If you want SNP to specify the sources of supply during conversion, and you are planning with an automatically generated SNP PPM, the system automatically uses the basic PP/DS PPM.

Define the lot-size interval of a PP/DS PPM, for example, based on the process-related or technical creation restrictions. Use the PP/DS minimum lot size as the SNP minimum lot size. As maximum lot size, specify in the SNP PPM the total quantity that can be produced in one day.