Production Planning and Control in Advanced Manufacturing

Posted on Aug 24, 2024 in Economy

Stocks in Store

You must have a specified number of items in stock. This number, while potentially reduced, should account for variations in consumption or delays in replenishment orders that could interrupt manufacturing and lead to financial losses. While there are several classifications of stored products, here are some examples:

  • Raw materials and auxiliary materials, intermediate products, ancillary materials, tools, finished products, and byproducts.
  • Cyclic, normal or planned reserves, excess, obsolete, and recovered stocks.

Scheduled Existence

This is calculated by the company to maintain the allowed pace for manufacturing or sales and represents the average value of stocks in store throughout the year.

Reserve Stock

This prevents the halt of the entire production process due to altered conditions in batch replenishment supply, such as delays or extended use of estimated materials.

In general terms, the buffer stock is high for low-value items and low for high-cost items.

Stocks to Extinguish

This consists of all items that should be discarded due to obsolescence, the emergence of substitute materials, or other various causes.

Production Control

Planning and production control in advanced manufacturing is based on the importance of human resources in the company. Personal checks disappear, replaced by individual and collective efforts of workers and their creative energy.

To implement the system requires:

  • Motivating and training workers.
  • Applying the philosophy of the “Olympic Zeros,” based on:
    • Zero defects: in materials or production.
    • Zero breakdowns and unemployment: through well-maintained and, if necessary, excess machinery.
    • Zero dead time: reducing preparation time.
    • Zero stock: distributing the factory into sub-plants.
    • Zero roles: the system is developed according to manufacturing needs.

Point of Order

The minimum order point for materials is determined by:

  • Consumption of materials (C)
  • Duration of reset time (Tr)
  • Risk (K)

General formula of the point of order: PP = K * C * Tr

If C is maximal (CM) and the delay Tr is maximum (TM), there is no risk of material stoppage, but there might be excess volume in the warehouse.

For materials requested when stocks reach the store value:

  • PP = CM * TM (for maximum values)
  • PP = Cm * Tm (for minimum values)

The amount will always be affected by stoppages due to unavailability. Points of order are made taking into account the normal values of consumption and time, affected by the coefficient K, which allows the stock manager to achieve the lowest possible cost for production processes.

PP = K * CN * TN

PERT

PERT (Program Evaluation and Review Technique) is based on the theory of networks and circuits to improve the utilization of resources employed in production.

The approach to any problem using PERT requires these steps:

  • Dividing the work into activities or tasks. The level of detail depends on the project’s magnitude.
  • Establishing relationships between activities, indicating the order of execution.
  • Determining the time needed to perform each activity.
  • Drawing the graph.
  • Defining the critical path.

Critical Path

These are the activities that require close monitoring to ensure the project stays on schedule. It is the longest path connecting the initial node to the end node and is characterized by activities with no slack.

It is important to monitor critical activities:

  • **In the preliminary calculation:** Attempt to reduce the times of critical activities and consequently the total duration of the work.
  • **During execution:** Any delay in a critical activity will delay the entire project.

The time corresponding to each node of the critical path is calculated as follows: starting from the source node and following the arrows, the sum of all paths leading to that node is placed in the bottom box (if multiple). The time indicated on the final node represents the total time needed to complete the work.

Planning Systems

Traditional and advanced manufacturing systems are the most commonly used for preparing documents for planning and production control.

The traditional system (most used in Spanish industry), conducted manually, mechanically, or by computer, is based on checks and tasks of individual operators. Workers perform various tasks using organizational techniques and are encouraged with performance-based bonuses.

The advanced manufacturing system integrates planning and production control with other areas of the company through computer systems.

1. Descriptive Memory

  • 1.1 Project Objective
  • 1.2 Owner
  • 1.3 Location
  • 1.4 Regulations and Standards Applied
  • 1.5 General Characteristics of the Industrial Installation
  • 1.6 Activity Characteristics
  • 1.7 Regulations for Troublesome, Unhealthy, Harmful, and Dangerous Activities
  • 1.8 Other Paragraphs Affecting the Installation and Automation in the Production Line
  • 1.9 Electrical Installation: Low Voltage Lighting Power
  • 1.10 Automation Line Installation
  • 1.11 Preventive Maintenance
  • 1.12 Programming and Execution of the Production Line, Performance Monitoring of the Implementation

Programming Labor

  • Technical characteristics of the elements used in the installation
  • Load Plan of the production line
  • Drawings and diagrams of the production line
  • Programming and control panel

II. Calculation Memory

  • II.1 Load of electrical installation
  • II.2 Sanitation

III. Levels

  • III.1 Location maps
  • III.2 Location map
  • III.3 Boundedness of the ship
  • III.4 Grafcet security diagram (power, hydraulic, pneumatic …)
  • Energy distribution
  • Wiring diagrams of the inputs and outputs of automata
  • Organizational aid to diagnosis.