By Julie Fraser

Many manufacturers seek supply chain tools to support at least some make-to-order, assemble-to-order, or configure-to-order production. Advanced planning and scheduling (APS) is a natural fit — the software handles variety and volatility in material requirements and production processes. However, you must evaluate solutions carefully, as the specific features that to-order manufacturers need are not available in all products. Unfortunately, most APS suppliers try to sell in a broad range of markets and it's hard to discern which have to-order features. To add to the confusion, the products that target complex to-order manufacturing are split between a scheduling-oriented and a planning-oriented focus.

To determine system selection criteria, each plant must also identify: its real constraints; overlap between cycles for orders, materials and production; the trading partner who paces the supply chain; and customer order acceptance and production modes. Most software products are best suited to certain combinations of conditions, but the marketing materials may not indicate that. (Note: Some engineer-to-order companies are benefiting from APS, but converting an engineering concept into BOM and work steps — the inputs to create plans and schedules — is still a research project.)

Given the split between planning and scheduling in products focusing on complex, to-order environments, buyers must ask, "Do I need planning, scheduling, or both?" My abbreviated definitions of these follow:

• Planning aggregates orders; determines what to build and roughly when; and defines the environment.
• Scheduling decides specifically when to build each order, in what sequence and with what machines, tools and people.

Finite scheduling contributions
In a to-order environment, actual customer orders determine what to build and when (the plan), so scheduling could be viewed as the more critical element. Scheduling can be especially powerful for a to-order company that acts as the pacer in the supply chain.

Examples of to-order issues that selected scheduling systems solve include:

• Achieves short production cycle times — Ideally, production is faster than market-acceptable delivery lead times in to-order; shortening cycles is a core functionality of some synchronizing schedulers.
• Supports changing demand order-by-order — For excellent customer service, scheduling gives visibility to individual orders throughout the production cycle.
• Synchronizes order components — Timing sub-product production to final assembly or multiple products for simultaneous shipment as a single order is available from only a few products that include backward schedulers and special linking logic.
• Supports focused factories — Companies that have simplified to cellular manufacturing may abandon planning concepts for configuration and scheduling. Configuration Systems & Consulting has "machine-to-order" customers using cell scheduling and ATP with its configurator.
• Assembly and Feeder line coordination — Assembly lines for to-order (i.e., trucks, heavy equipment) demand custom sequencing logic and feeder line coordination. Optimax has several successful assembly line customers.

Advanced planning contributions
Many to-order environments are plagued by an imbalance between long lead times on the materials supply side (suppliers pace the supply chain) and very short turnaround expectations from customers. Where material availability is a primary constraint, planning-centric products with roots in MRP simulation provide strong benefits.

• Perpetual Customer Feedback — Materials planning-oriented systems allow a company to inform customers of their ability to handle upside or downside demand changes.
• ATP Inside Material Supply Time — Promising customer order delivery dates inside of the lead time for key materials is a primary use for MRP simulation products such as ProMIRA's.
• Long lead-time material planning — Minimizing the risk of materials stock-outs and obsolescence is possible with "reverse MRP" products such as IBM's PRM.
• Plan Comparisons — In setting policy, it's often helpful to compare more than two plans to evaluate various combinations of factors, a feature Enterprise Planning Systems customers use.
• "Capable-to-promise" goes beyond checking availability, to ensure best dates while still keeping existing commitments. There are both planning and scheduling systems that do this by generating a planning or phantom order, with its associated BOM and routing, and simulating the impact.

Most APS products do not support the to-order demands described above. In our work, we see APS mismatches between product strengths and user needs. No matter what the environment, software buyers must define their environment and most pressing problems, and evaluate the vendor solution critically. Make sure the APS system meets your particular set of needs — the software is not to order.