Production Planning and Control Systems

Production  Planning and  Control Systems

CHAPTER CONTENTS

Aggregate Production Planning and the Master Production Schedule

 Material Requirements Planning

Inputs to the MRP System

How MRP Works

MAP Outputs and Benefits

 Capacity Planning

 Shop Floor Control

 Order Release

 Order Scheduling

 Order Progress

 Factory Data Collection System

 Inventory Control

 Order Point Inventory Systems

 Work in Process Inventory Costs

Manufacturing Resource Planning (MRP II)

Just ln Tirne Production Systems

 Pull System of Production Control

 Small Batch Sizes and Reduced Setup Times

 Stable and Reliable Production Operations

Production planning and control (PPC) is concerned with the logistics problems that are encountered in manufacturing, that is, managing the details of what and how many products to produce and when, and obtaining the raw materials, parts, and resources to product those products. PPC: solves these logistics problems by managing information. The computer is essential for processing the tremendous amounts of data involved to define the products and the manufacturing resources to produce them and to reconcile these technical details with the desired production schedule. In a very real sense. PPC is the integrator in computer integrated manufacturing

Planning and control in PPC must themselves be integrated functions.!t is insufficient to plan production if there is no control of the factory resources  achieve the plan, And it is ineffective to control production if there is no plan against which to compare factory progress. Both planning and control must be accomplished .ano they must be coordinated with each other and with other functions in the manufacturing firm. such a, process planning, concurrent engineering. and advanced manufacturing planning (Chapter 25). Now, having emphasized the integrated nature of  PPC. let us nevertheless try to explain what is involved in each of the two function" production planning and production control.

Production planning IS concerned with: (1) deciding which products to make, how many of each, and when they should he completed: (2) scheduling the delivery and/or production of the pans and products: and (3) planning the manpower and equipment resources needed to accomplish the production plan. Activities within the scope of production planning include

   Aggregate production planning. This involves planning the production output levcts for major product lines produced by the firm. These plans must be coordinated among various functions in the firm, including product design, production, marketing and sales

   Master production planning. The aggregate production plan must be converted into a master production schedule (\1PS) which is a specific plan of the quantities to be produced of individual models within each product line.

   Material requirements planning (MRP) is a planning technique, usually implemented by computer that translates the MPS of end products into a detailed schedule for the raw materials and parts used in those end products

   Capacity planning is concerned with determining the labor and equipment resources needed to achieve the master schedule.

Production planning activities divide into two stages: (1) aggregate planning which results in the MPS, and (2) detailed planning. which includes MRP and capacity  planning. Aggregate planning involves planning 6 months or more into the future. whereas detailed planning is concerned with the shorter term (weeks to months)

Production control is concerned with determining whether the necessary resources 10 implement the production plan have heen provided, and if not. it attempts to take corrective action to address the deficiencies. A, its name suggests, production control includes various systems and techniques for controlling production and inventory in the factory. The major topic, covered in this chapter are:

   Shop floor control. Shop floor control systems compare the progress and status of production orders in the factory to the production plans (MPS and parts explosion accomplished by MRP)

• Inventory control. Inventory control includes it variety of techniques fur managing the inventory of a firm. One of the important tools in inventory control is the economic order quantity formula

   Manufacturing resource planning. Also known as MRP II. manufacturing resource planning combines MRP and capacity planning as well as shop Iloor control and other functions related to PPC

   Just In time production systems. The term "just in time" refers 10 a scheduling discipline in which materials and parts are delivered to the next work cell or production line station just prior to their heing used. This type of discipline tends to reduce inventory and other kinds of waste in manufacturing.