Introduction to Long-Term Planning: Purpose and Simulative Planning Concept
Understand why Long-Term Planning exists, how it differs from operative MRP, and how simulative versions let planners test demand scenarios safely.
Explanation
Long-Term Planning (LTP) is SAP PP's mechanism for simulating future material and capacity requirements without affecting operative data such as stock, purchase requisitions, or planned orders used in production execution. Organizations need to answer questions like: if we accept this new sales forecast, do we have enough capacity next quarter? Will a new product line create a bottleneck at a specific work center? Can our vendors support the raw material volumes implied by an aggressive growth plan? Answering these questions using operative MRP is dangerous because operative MRP creates real planned orders and purchase requisitions that procurement and production will act on. LTP solves this by working entirely in a simulative environment. The foundation of LTP is the planned independent requirement (PIR). In operative planning, PIRs represent the demand plan used to drive MRP. LTP introduces simulative versions of independent requirements, which are separate from the operative (usually version 00) PIRs. A simulative version is essentially a sandbox demand plan: a planner can create version 'LT1' or similar, populate it with an aggressive or conservative forecast, and run planning against only that version. The operative version remains untouched, and production continues to execute against real orders as normal. A long-term planning scenario groups together the simulative requirements version, a validity period, and planning parameters (such as which plants, MRP areas, and BOM/routing alternatives to consider). Once a scenario is created, the planner triggers an MRP-like run confined to that scenario. This run explodes BOMs and routings just like operative MRP, generating simulative planned orders and purchase requisitions, but none of these interact with real inventory or trigger actual procurement. The system calculates capacity loads at work centers based on the routing operations tied to these simulative orders, which is the primary output planners care about: capacity evaluation. Why does this matter at a beginner level? Because LTP is frequently confused with simple demand management or with running MRP in a 'test mode.' It is neither. It is a fully separate planning universe with its own requirement types, its own order categories, and its own evaluation transactions. A new PP consultant must understand that master data (materials, BOMs, routings, work centers) is shared between operative and simulative planning, but the transactional data (requirements, orders, capacities) is kept apart through the versioning mechanism. LTP is commonly used to support Sales and Operations Planning (S&OP) processes, capacity investment justification, make-or-buy decisions, and long-range material sourcing negotiations with vendors. In many implementations, LTP results are exported to spreadsheets or BI tools for executive review rather than acted upon directly in the SAP system. Understanding this business purpose is essential before diving into scenario configuration, because a consultant who treats LTP purely as a technical exercise will miss the real value it delivers: safe, risk-free scenario testing at scale. Finally, it's important to set expectations about complexity. LTP evaluations depend on the same master data quality (accurate routings, correct work center capacities, valid BOM explosions) as operative planning. Garbage master data produces garbage simulation results just as it would in production MRP. Many failed LTP initiatives are not failures of the LTP functionality itself but failures of underlying master data governance.
Real project scenario
A discrete manufacturer preparing next year's budget wanted to test whether a proposed 30% growth in one product family could be supported by existing press and assembly capacity before committing to capital equipment purchases. The PP consultant created a simulative independent requirements version reflecting the growth forecast, built a long-term planning scenario referencing only the affected plant and MRP areas, and ran the LTP MRP simulation. The resulting capacity evaluation showed a clear bottleneck at one work center starting in month four, giving the operations team concrete data to justify a capacity expansion request three months ahead of when the constraint would have surfaced in real operative planning.
Common mistakes
• Confusing LTP simulative versions with operative demand management versions and accidentally basing real MRP runs on simulative data. • Assuming LTP results are stored in the same tables as operative planned orders, leading to confusion when simulative orders don't appear in standard operative order lists. • Running LTP without first validating that BOMs and routings used in the scenario are current, resulting in misleading capacity forecasts. • Treating LTP as a one-time report rather than a repeatable process tied to periodic S&OP cycles. • Expecting LTP to automatically feed procurement or shop floor execution, when in fact a deliberate transfer step to operative data is required if results are to be acted upon.
Best practices
• Always use a dedicated simulative requirements version per planning scenario to keep scenarios isolated and auditable. • Validate master data currency (BOM/routing/work center capacity) before running any LTP scenario intended for business decision-making. • Document the business assumptions behind each simulative version (e.g., growth rate, new product ramp-up) so results can be interpreted correctly later. • Align LTP cycles with the organization's S&OP calendar so results are timely and relevant to real decisions. • Communicate clearly to stakeholders that LTP output is advisory and simulative, not an automatic trigger for procurement or production activity.
Interview angle
Interviewers commonly ask candidates to explain the difference between operative MRP and Long-Term Planning, and to describe what a simulative version of independent requirements is used for. A strong answer distinguishes the sandboxed nature of LTP data, explains that BOMs/routings/work centers are shared master data while requirements and orders are versioned separately, and gives a concrete business scenario such as capacity planning for a new product launch or budget cycle validation.