Computer integrated manufacture
What is it?
takes the concept of integration of separate manufacturing technologies developed by FMS a step further by combining all company operations, not just those that are directly involve in manufacture. Under CIM all teams can share the same info and easily communicate. A CIM system uses computer networks combine processing of production and business info with manufacturing operations to create co-operation and smooth running production lines.
Tasks within CIM are:
- design of product using CAD
- planning the most cost effective work-flow
- controlling the operations of machines and equipment needed to manufacture the product
- performing business functions such as ordering stock and materials and invoicing customers
One of the drawbacks is CIM's dependence on computer data to fully integrate all operations. The cost of managing data is also a key issue because if it becomes corrupted, machinery may malfunction. To prevent this companies use a product data management (PDM) system.
Product Data Management (PDM)systems within CIM
PDM is an information system used to manage the data for a product as it passes from design to manufacture. It includes plans, CAD drawings, 3D models, CNC programs and all the related project data documents. It also highlights when changes are made to a database so that effects on other parts can be determined. PDM systems support efficient production by helping cmpanies manage data.
- Reduced time to market- as data is instantly available to all teams for review, eliminating "bottlenecks" where documents await distrubution or sign-off
- improved productivity- as changes to product data are tracked and managed automatically, reducing search and retrieving time for documents and giving the ability to reuse design data without repeating work.
- improved control- due to efficient management systems that assure everyone is working from the most current data.
Enterprise resource planning systems (ERP) within
ERP systems attempt to combine all the software and data from various departments into one system that all can use. ERP improves the way in which a company takes a customer order and processes it into an invoice. It takes customer orders and provides a software "road map" for automating the different steps along the path to fulfilling it. e.g.
When a customer order is entered into an ERP system, all the information necessary to complete the order is instantly accessible, such as customer credit rating, order history from the finance department, stock levels from the warehouse department and the delivery schedule from the logistics department. Employees in the different departments all see the same info and can update it instantly. When one department finishes with the order, it is automatically sent via the ERP system to the next department. Therefore any order can be easily tracked and customers should receive delivery of their orders faster without errors.
ERPs are expensive to install, and it costs a lot to invest in hardware and staff training. The success depend s on the skill and experience of staff and quality of ongoing training.
Lean Manufacturing & Just in time (JIT) systems
Lean manufacturing aims to provide techniques that ensures minimum waste is incurred during production and to produce products only when they are needed. This is why it uses (JIT), materials arrive just when they are needed, to reduce overstocking and save warehouse space and storage costs.
5 Key stages of lean manufacturing
- Value- focus on value in terms of what the customer is prepared to pay for.
- Value stream- how changing the value affects the efficiency of throughout production including: 1) value adding activities: machining, processing, painting, assembling etc 2) non value adding activities: scrapping, sorting, storing, counting, moving etc
- Flow- design processes that result in uninterrupted flow
- Pull- design manufacturing for "pull" of product through the process as a response to demand
- Perfection- adopt an approach that continually improves working processes.
Pull tools- Kanban, Perfection Tools-Kaizen
Kanban uses cards or containers as visual signals to indicate when to pull materials, components or products through the production system. It relies on a simple rule of only producing or delivering when a card or a container is passed to a workstation or manufacturing cell. Production kanban and transportation kanban are combined into 1 integrated system.
- Production kanban- includes details of the operations that need to be carried out at the workstation or manufacturing cell
- transportation kanban- only contains details regarding where the materials, components or products have come from and where they are going to.
Main benefit of using Kanban is that it reduces the amount of work-in-progress and finished goods in stock. Kanban restricts the supply of materials and components until they are needed, which provides an effective JIT systems
- is also known as a continuous improvement, where small changes are made to the production process resulting in small improvements being made. This system is carried out on a regular basis as the changes mad are often low cost and the improvements made tend to be small.
Flexible Manufacturing Cells
- Lean manufacturers must be flexible in order to meet the demand variety of customers. Manufacturing cells allow manufacturers to provide their customers with the roght product at the right time. They achieve this by grouping similar products into families that can be processed on the sam equipment in the same sequence.
- A manufacturing cell is a group of workstations, arranged such that a product can be processed progressivley from 1 workstation to another without having to wait for a batch, and without additional handling between operations.
- Cell production methods provide flexibility as upgrades to processes can be performed quickly and easily by shutting down one cell whilst others simultaneously opens & takes its place. this means the entire production line doesn't have to be disrupted, which reduces costs from stoppages or "downtime".
- Flexibility occurs when a large varieyt of products are assembled from a range of similar components.
- A manufacturing cell usually contains 3-12 workers and 5-15 workstations in a compact arrangement.
- Some cells are fully automated using CAM with several CNC machines, computer aided quality control and automated machine handling systems.
- Functional cells- these cells perfom a specific function as opposed to manufacturing a complete product. They consist of similar equipment. For example, a factory that carries out machine operations only may have a bank of lathes together in a "turning cell".
- Group technology cells- these cells perform a series of operations for several different production lines. The products often have similar manufacturing operations though not usually identical.These cells can work well within a lean manufacturing environment, particularly if the company is characterised by a large product range with low volume.
- Product focused cells- these cells are product focused and typically manufacture one type of product through a series of operations. These are ideal for lean manufacturing and are perfect for a small product range with high volume manufacturers.
Computer aided Quality control (CAQ)
- CAQ can be achieved in a manufacturing cell using a coordinate-measuring machine (CMM).
- A CMM is a mechanical system designed to move a measuring probe to determine the coordinates of points on the surface of a workpiece to accurately measure the sizes and positions of features on mechanical parts. This provides data that can immediately be fed back to analyse extremely small tolerances and control the quality of components.
- Laser technology can be used to check size and position, and to create 3D images.
Automated materials-handling systems
- is a device that takes materials from one place to another, such as a conveyor belt or truck.
- start with the unloading of goods from delivery transportation.
- The goods then go through storage, onto machining, assembly, testing, packaging and finally loading back onto transport for delivery.
- each of the stages of the production process requires a slightly different design of handling equipment
- fully automated handling systems ensure that the materials, components and assemblies are delivered to the production line when required without significant manual intervention.
Automatic storage and retrieval systems (ASRS)
- is an automated robotic system for sorting, storing and retrieving items in a warehouse.
- within CIM, transportation of components to the required points are controlled by computer.
- stocks of materials are stacked in racking systems. ASRS selects the correct component from the rack, retrieves it by a crane and places it on a conveyor belt or AVG for transportation.
- Once completed, products ar taken to a warehouse and from there they are distributed. Warehousing and distribution are about getting as many products as possible to market, in the shortest time possible.
- ADVANTAGES- increased efficiency of storage and retrieval and reduced labour costs, employees' technical skills are developed in the operation of a system
Automated guided vehicles (AVG)
An AVG is a materials-handling device that is used to move parts between machines or work-centres. They are small independantly powered vehicles that are usually guided by radiofrequency wires buried in the floor or use optical sensors in a laser-guided navigation system. They are controlled by recieving instructions either from a central computer or from their own on board computer.
- towing vehicles- pull a variety of trailer types
- Unit load vehicles- equipped with decks that permit unit load transportation and automatic load transfer. the decks can either be lift and lower, powered/non powered roller etc.
- Pallet trucks- transports palletised loads to/from floor level, eliminating the need for fixed load stands.
- Fork Truck- services loads both at floor level and on stands. Can also stack loads in a racking system.
- Light Load- transports small parts through a light manufacturing environment and small spaces
- Assembly line vehicles- used for assembly processes such as manufacturing cells.
Impact of advanced manufacturing technology on emp
- there has been reduction of workforces as machines have become more efficient.
- but high skilled workers are still needed e.g. product designers, engineers, CNC programmers
- computers increase the skill in manufacturing professionals who use advanced productivity, visualisation and simulation tools.
Arguments for and against Manufacturing jobs:
Myth 1: Manufacturing jobs are monotonous, strenuous and low paid
- for: they are endless assembly lines employing poorly paid manual workers who carry out the same mundane task year on.
- against: increase in automated production lines has lead to a demand of increased flexibility and skill among staff. A multi-skilled workforce is needed to service a challenging and diverse industry.
Myth 2: Manufacturing is not a creative industry
- everything that is manufactured has to be designed. All components need to be functionally and creatively designed for purpose