Computer Aided Process Planning And Control And Computer Monitoring

COMPUTER AIDED PROCESS PLANNING AND CONTROL AND COMPUTER MONITORING

Demand for information and automation systems in manufacturing is soaring. Systems in demand include programmable controls, robotic systems, supervisory controls, data acquisition and information management systems. These systems deliver high-quality, reliable and repeatable solutions to our customers, improving their processes. In our work designing and implementing these systems, we have observed ten important emerging trends:

Production Planning and control;

Production planning and control may be defined as the direction as the direction and coordination of a firm’s material and physical facilities towards the

attainment  of  pre specified Production of goods, with production efficiency.

Production planning;

Deciding  which  products  to  make,  how  many  of  each,  and  when  they  should

be completed. Planning  the  manpower  and  equipment  resources  needed  to  accomplish

the  production plan. Scheduling the production and delivery of the parts and products ;

Production control;

Production control is concerned with determining whether the necessary resources to implement the production plan have been provided or not.

Activities of production control;

·        Shop floor control;

·        Inventory control;

·        Manufacturing resource planning (MRP II); and

·        Just-in-time manufacturing systems. The term production system may refer to:

·        In operations management and industrial engineering, a production system comprises both the technological elements (machines and tools) and organizational behavior (division of labor and information flow) needed to produce something.

·        In computer science, a production system (or production rule system) is a computer program typically used to provide some form of artificial intelligence.

·        Toyota Production System, organizes manufacturing and logistics at Toyota

·        The Computer Animation Production System (CAPS) is a proprietary collection of software, scanning camera systems, servers, networked computer workstations, and custom desks developed by The Walt Disney Company together with Pixar in the late-1980s.

·        Subsea Production Systems are typical wells located on the sea floor, shallow or deep water.

Production control is the activity of monitoring and controlling any particular production or operation. Production control is often run from a specific control room or operations room

Role of Production Control in the Production Cycle.

Basic Process Control Strategies

In a simple control system, a process variable (PV) is measured and compared with a setpoint value (SP). A manipulated variable (MV, or output) signal is generated by the controller and sent to a final control element, which then influences the process variable to achieve stable control. The algorithm by which the controller develops its output signal is typically PID (Proportional-Integral-Derivative), but other algorithms may be used as well:

This form of simple control may be improved upon and expanded for a greater range of process applications by interconnecting multiple controllers and/or redirecting measurement and control signals in more complex arrangements. An exploration of some of the more common control system configurations is the subject of this chapter.

Inventory management in CIM

Definition - Inventory

Inventory management is primarily about specifying the size and placement of stocked goods. Inventory management is required at different locations within a facility or within multiple locations of a supply network to protect the regular and planned course of production against the random disturbance of running out of materials or goods.

The lead time, carrying costs of inventory, asset management, inventory forecasting, inventory valuation, inventory visibility, future inventory price forecasting, physical inventory, available physical space for inventory, quality management, replenishment, returns and defective goods and demand forecasting and also by replenishment Or can be defined scope of inventory management also concerns the fine lines between replenishment as the left out stock of any item used in an organization. inventory is liabilities of a business.

The overseeing and controlling of the ordering, storage and use of components that a company will use in the production of the items it will sell as well as the overseeing and controlling of quantities of finished products for sale. A business's inventory is one of its major assets and represents an investment that is tied up until the item is sold or used in the production of an item that is sold. It also costs money to store, track and insure inventory. Inventories that are mismanaged can create significant financial problems for a business, whether the mismanagement results in an inventory glut or an inventory shortage.

Inventory or stock refers to the goods and materials include that a business holds for the ultimate purpose of resale (or repair).

Inventory management is a science primarily about specifying the shape and percentage of stocked goods. It is required at different locations within a facility or within many locations of a supply network to precede the regular and planned course of production and stock of materials.

The scope of inventory management concerns the fine lines between replenishment lead time, carrying costs of inventory, asset management, inventory forecasting, inventory valuation, inventory visibility, future inventory price forecasting, physical inventory, available physical space for inventory, quality management, replenishment, returns and defective goods, and demand forecasting. Balancing these competing requirements leads to optimal inventory levels, which is an ongoing process as the business needs shift and react to the wider environment.

Inventory management involves a retailer seeking to acquire and maintain a proper merchandise assortment while ordering, shipping, handling, and related costs are kept in check. It also involves systems and processes that identify inventory requirements, set targets, provide replenishment techniques, report actual and projected inventory status and handle all functions related to the tracking and management of material. This would include the monitoring of material moved into and out of stockroom locations and the reconciling of the inventory balances. It also may include ABC analysis, lot tracking, cycle counting support, etc. Management of the inventories, with the primary objective of determining/controlling stock levels within the physical distribution system, functions to balance the need for product availability against the need for minimizing stock holding and handling costs.

Definition - Inventory management

Inventory management is primarily about specifying the size and placement of stocked goods. Inventory management is required at different locations within a facility or within multiple locations of a supply network to protect the regular and planned course of production against the random disturbance of running out of materials or goods.

The scope of inventory management also concerns the fine lines between replenishment lead time, carrying costs of inventory, asset management, inventory forecasting, inventory valuation, inventory visibility, future inventory price forecasting, physical inventory, available physical space for inventory, quality management, replenishment, returns and defective goods and demand forecasting and also by replenishment Or can be defined as the left out stock of any item used in an organization. inventory is liabilities of a business.

Inventory Control;

Inventory Control is the supervision of supply, storage and accessibility of items in order to ensure an adequate supply without excessive oversupply.

It can also be referred as internal control - an accounting procedure or system designed to promote efficiency or assure the implementation of a policy or safeguard assets or avoid fraud and error etc.

Inventory control may refer to:

In economics, the inventory control problem, which aims to reduce overhead cost without hurting sales.

In the field of loss prevention, systems designed to introduce technical barriers to shoplifting

Inventory or stock refers to the goods and materials that a business holds for the ultimate purpose of resale (or repair).

Inventory management is a science primarily about specifying the shape and percentage of stocked goods. It is required at different locations within a facility or within many locations of a supply network to precede the regular and planned course of production and stock of materials.

Material requirements planning (MRP) in CIM;

It is a production planning, scheduling, and inventory control system used to manage manufacturing processes. Most MRP systems are software-based, while it is possible to conduct MRP by hand as well.

An MRP system is intended to simultaneously meet three objectives:

·        Ensure materials are available for production and products are available for delivery to customers.

·        Maintain the lowest possible material and product levels in store

·        Plan manufacturing activities, delivery schedules and purchasing activities.

History Of MRP

Prior to MRP, and before computers dominated industry, Reorder point (ROP) / reorder-quantity (ROQ) type methods like EOQ (Economic Order Quantity) had been used in manufacturing and inventory management. In 1964, as a response to the Toyota Manufacturing Program, Joseph Orlicky developed Material Requirements Planning (MRP). The first company to use MRP was Black & Decker in 1964, with Dick Alban as project leader. Orlicky's book Material Requirements Planning has the subtitle The New Way of Life in Production and Inventory Management (1975). By 1975, MRP was implemented in 700 companies. This number had grown to about 8,000 by 1981.

In 1983 Oliver Wight developed MRP into manufacturing resource planning (MRP II).[1]In the 1980s, Joe Orlicky's MRP evolved into Oliver Wight's manufacturing resource planning (MRP II) which brings master scheduling, rough-cut capacity planning, capacity requirements planning, S&OP in 1983 and other concepts to classical MRP. By 1989, about one third of the software industry was MRP II software sold to American industry ($1.2 billion worth of software).[2]

Functions of MRP;

The basic functions of an MRP system include: inventory control, bill of material processing, and elementary scheduling. MRP helps organizations to maintain low inventory levels. It is used to plan manufacturing, purchasing and delivering activities.

"Manufacturing organizations, whatever their products, face the same daily practical problem - that customers want products to be available in a shorter time than it takes to make them. This means that some level of planning is required."

Companies need to control the types and quantities of materials they purchase, plan which products are to be produced and in what quantities and ensure that they are able to meet current and future customer demand, all at the lowest possible cost. Making a bad decision in any of these areas will make the company lose money. A few examples are given below:

·        If a company purchases insufficient quantities of an item used in manufacturing (or the wrong item) it may be unable to meet contract obligations to supply products on time.

·        If a company purchases excessive quantities of an item, money is wasted - the excess quantity ties up cash while it remains as stock and may never even be used at all.

·        Beginning production of an order at the wrong time can cause customer deadlines to be missed.

MRP is a tool to deal with these problems. It provides answers for several questions:

·        What items are required?

·        How many are required?

·        When are they required?.

MRP can be applied both to items that are purchased from outside suppliers and to sub-assemblies, produced internally, that are components of more complex items.

MRP - Function of MRP;

It is a planning technique. It translates the master production schedule (MPS) of end products into a detailed schedule for the raw materials and parts used in those end products.

BOM;

The bill of materials (BOM) designates what itemsand how many of each are used to make up a specified final product.

Benefits of MRP

The benefits of implementing MRP system are:

·        Reduced inventory levels.

·        Better Production scheduling

·        Reduced production lead time.

·        Better machine utilization.

·        Improved product quality.

Material requirements planning (MRP) is a production planning and inventory control system used to manage manufacturing processes. Most MRP systems are software-based, while it is possible to conduct MRP by hand as well.

An MRP system is intended to simultaneously meet three objectives:

1.     Ensure materials are available for production and products are available for delivery to customers.

2.     Maintain the lowest possible material and product levels in store

3.     Plan manufacturing activities, delivery schedules and purchasing activities.

Shop Floor Control

Shop floor control comprises the methods and systems used to prioritize, track, and report against production orders and schedules. It includes the procedures used to evaluate current resource status, labor, machine usage, and other information required to support the overall planning, scheduling, and costing systems related to shop floor operation. Shop floor control typically calculates work in process based on a percentage of completion for each order and operation that is useful in inventory valuations and materials planning.

Shop floor control is responsible for the detailed management of activities and the flow of materials inside the plant, including employees, materials, machines, and production time. Shop floor control activity typically begins after planning (e.g., with MRP, ERP); once planned, orders and purchase requisitions are created. Shop floor control attends to the following functions (sequentially):

·        Planned orders

·        Conversion of planned orders to process/production

·        Production and process order scheduling

·        Capacity requirements planning

·        Material availability assessment

·        Release of production/process orders

·        Material withdrawals

·        Order confirmations

·        Goods receipt documentation

·        Order settlement

Shop floor control may also include identifying and assessing vulnerabilities and risks due to the shop floor environment, employees, process, and the technologies employed at the shop-floor level. Based on the assessment of these factors, shop floor control initiates measures to keep risk at an acceptable minimum level.

Best practices for shop floor control include:

·        Efficiently execute, prioritize, and release work orders to the shop floor with real-time status of progress and completion.

·        Deliver accurate and up-to-date information on materials consumption and availability, which is essential for reliable inventory planning and costing.

·        Effectively execute change management processes to ensure that the proper revision of products, bills of materials, and processes are always in place for production.

·        Automate shop floor equipment control and data collection to reduce human errors and increase productivity.

·        Provide the correct manufacturing SOPs, technical drawings, and diagnostics to shop floor operators to reinforce training and ensure proper processing.

·        Download setup programs directly to equipment based on product and process specifications.

With fully interactive access to shop floor control software, supervisors can monitor shop activities and make better decisions on the spot, especially using mobile computing equipment.

Shop Floor Control are methods and systems used to prioritize, track, and report against production orders and schedules. They include the procedures used to evaluate current resource status, and the update of labor, machine hour, and other associated information as required to support the overall planning, scheduling, and costing systems.

Agile and Lean manufacturing in CIM

Agile manufacturing is a term applied to an organization that has created the processes, tools, and training to enable it to respond quickly to customer needs and market changes while still controlling costs and quality.

An enabling factor in becoming an agile manufacturer has been the development of manufacturing support technology that allows the marketers, the designers and the production personnel to share a common database of parts and products, to share data on production capacities and problems — particularly where small initial problems may have larger downstream effects.

It is a general proposition of manufacturing that the cost of correcting quality issues increases as the problem moves downstream, so that it is cheaper to correct quality problems at the earliest possible point in the process.

Agile manufacturing is a term applied to an organization that has created the processes, tools, and training to enable it to respond quickly to customer needs and market changes while still controlling costs and quality.

An enabling factor in becoming an agile manufacturer has been the development of manufacturing support technology that allows the marketers, the designers and the production personnel to share a common database of parts and products, to share data on production capacities and problems — particularly where small initial problems may have largerdownstream effects.

It is a general proposition of manufacturing that the cost of correcting quality issues increases as the problem moves downstream, so that it is cheaper to correct quality problems at the earliest possible point in the process.

Agile manufacturing is seen as the next step after Lean manufacturing in the evolution of production methodology. The key difference between the two is like between a thin and an athletic person, agile being the latter. One can be neither, one or both. In manufacturing theory, being both is often referred to as leagile.

According to Martin Christopher, when companies have to decide what to be, they have to look at the Customer Order Cycle (the time the customers are willing to wait) and the leadtime for getting supplies. If the supplier has a short lead time, lean production is possible. If the COC is short, agile production is beneficial.

Lean manufacturing or lean production, often simply "lean", is a systematic method for the elimination of waste ("Muda") within a manufacturing process. Lean also takes into account waste created through overburden ("Muri") and waste created through unevenness in work loads ("Mura"). Working from the perspective of the client who consumes a product or service, "value" is any action or process that a customer would be willing to pay for.

Essentially, lean is centered on making obvious what adds value by reducing everything else. Lean manufacturing is a management philosophy derived mostly from the Toyota Production System (TPS) (hence the term Toyotism is also prevalent) and identified as "lean" only in the 1990s TPS is renowned for its focus on reduction of the original Toyota seven wastes to improve overall customer value, but there are varying perspectives on how this is best achieved. The steady growth of Toyota, from a small company to the world's largest automaker, has focused attention on how it has achieved this success.

Agile manufacturing;

Agile manufacturing is a term applied to an organization that has created the processes, tools, and training to enable it to respond quickly to customer needs and market changes while still controlling costs and quality.

An enabling factor in becoming an agile manufacturer has been the development of manufacturing support technology that allows the marketers, the designers and the production personnel to share a common database of parts and products, to share data on production capacities and problems — particularly where small initial problems may have larger downstream effects. It is a general proposition of manufacturing that the cost of correcting quality issues increases as the problem moves downstream, so that it is cheaper to correct quality problems at the earliest possible point in the process.

Lean manufacturing ;

Lean manufacturing, Lean Enterprise, or lean production, often simply, "lean", is a production philosophy that considers the expenditure of resources in any aspect other than the direct creation of value for the end customer to be wasteful, and thus a target for elimination. Working from the perspective of the client who consumes a product or service, "value" is any action or process that a customer would be willing to pay for.

Direct digital control (DDC);

is the automated control of a condition or process by a digital device (computer). DDC is considered by many to be a more modern, granular and responsive update to older HVAC control systems based upon PLC technologies. In those older PLC based systems, each zone was self-sufficient and contained all of the instrumentation and control elements needed to consider analog and digital inputs and then take actions according to rules. The complexity came from the desire to expand these 'zones' from a few dozen points and a handful of controlled elements to much broader building-wide systems. Connecting PLCs together becomes complex, and the creation of rules which would be loaded individually into each PLC impractical.

DDC on the other hand takes a more centralized network-oriented approach. All instrumentation is gathered by various analog and digital converters which use the network to transport these signals to the central controller.

The centralized computer then follows all of its production rules (which may incorporate sense points anywhere in the structure) and causes actions to be sent via the same network to valves, actuators, and other HVAC components that can be adjusted.

Central controllers and most terminal unit controllers are programmable, meaning the direct digital control program code may be customized for the intended use. The program features include time schedules, setpoints, controllers, logic, timers, trend logs, and alarms.

The unit controllers typically have analog and digital inputs, that allow measurement of the variable (temperature, humidity, or pressure) and analog and digital outputs for control of the medium (hot/cold water and/or steam). Digital inputs are typically (dry) contacts from a control device, and analog inputs are typically a voltage or current measurement from a variable (temperature, humidity, velocity, or pressure) sensing device.

Digital outputs are typically relay contacts used to start and stop equipment, and analog outputs are typically voltage or current signals to control the movement of the medium (air/water/steam) control devices. Usually abbreviated as "DDC".

It is the automated control of a condition or process by a digital device (computer).

A very early example of a DDC system meeting the above requirements was completed by the Australian business Midac in 1981-1982 using R-Tec Australian designed hardware.

Basically, lean manufacturing technique consists of four steps. First step is to realize that there are wastes in the system to be removed. Although this seems like a crazy idea, this is the step which creates the requirement for the movement towards lean manufacturing. Many organizations do not realize that they have tons of hidden wastes with them. Therefore they do not have the requirement to remove them from the system. So they will have their problems forever and they will try to find solutions for these problems forever.