Content

• The differences between a:

– model

– prototype

– marketable product.

• The preparation of a design brief for a marketable product.

• The preparation of a manufacturing specification used to make a product in quantity.

• The differences between individual (one-off), batch and mass production systems and how each impact

on the:

– product

– people involved

– resources and costs.

• Commercial manufacturing systems, including:

– concurrent engineering

– computer-integrated manufacturing (CIM) and computer-integrated engineering (CIE)

– cell production

– in-line assembly

– just in time (JIT)

– logistics.

• The design of a manufacturing system, including jigs and formers, to be used to make a product in

quantity.

• Strategies to evaluate how well a manufacturing system has worked.

• Improvements to a manufacturing system, including the use of templates to mark out shapes repeatedly

and jigs and formers used to make a product.

• Continuous improvement processes, such as KaizenTM.

The differences between a model, prototype, and a marketable product.

Model

A model is the earliest, most basic representation of an idea. Its primary purpose is conceptual, designed to test a fundamental principle or a single aspect of the product, such as its appearance or general form. It is not functional and is typically used for internal review, brainstorming, or presentation to stakeholders.

• Key Characteristics:

  • Purpose: To explore a concept.

  • Audience: Internal team members, designers, or investors.

  • Functionality: Non-functional.

  • Example 1 (Physical Product): A miniature, non-working replica of a new car design, used to visualize its shape and aerodynamics in a wind tunnel.

  • Example 2 (Digital Product): A simple wireframe or flowchart for a mobile app, showing the basic user flow and screen layout without any visual design or functionality.

Prototype

A prototype is the first functional version of a product, built to test and refine its design, features, and user experience. It may not have the final appearance or quality of the finished product, but it proves that the core concept works. Prototypes are used for testing with real users to gather feedback and identify flaws.

• Key Characteristics:

  • Purpose: To test functionality, usability, and design.

  • Audience: Internal teams and a small group of test users.

  • Functionality: Partially or fully functional, but often with bugs or rough features.

  • Example 1 (Physical Product): A 3D-printed version of a drone that can fly and record video but has an unfinished shell, exposed wiring, and a short battery life.

  • Example 2 (Digital Product): A "clickable" mockup of a website created in a design tool like Figma, allowing users to navigate through pages and interact with buttons to simulate the user experience.

Marketable Product

A marketable product is the final, polished, and fully functional version ready for sale and distribution to the general public. It has passed all testing, meets quality standards, and is designed to provide a reliable, complete user experience. This is the version that generates revenue for the company.

• Key Characteristics:

  • Purpose: To solve a problem and generate revenue.

  • Audience: The target consumer or customer base.

  • Functionality: Fully functional, stable, reliable, and high-quality.

  • Example 1 (Physical Product): The latest iPhone, which is mass-produced, packaged, and sold in stores with a polished design, complete functionality, and customer support.

  • Example 2 (Digital Product): A fully launched mobile app that is available on an app store, is stable, regularly updated, and has a complete set of features for its users.

Summary of Differences

Introduction

Designers and manufacturers have to be conscious of the scale of production for any of their intended products, since this will have an important bearing on decisions that are made about its design and manufacture.

The use of ICT in manufacture can be expensive and time consuming so it is important to consider the different scales of production that can be used. After all, it is not always feasible to invest in CAD/CAM

equipment for smaller scale production.

Manufacturing efficiency is often improved by incorporating sub-assemblies, which are pre-made elements of a product, or bought in components in the final assembly process.

a manufacturing specification used to make a product in quantity as opposed to a design specification.

A design specification outlines the requirements and criteria a product must meet to be successful, focusing on the problem to be solved, while a manufacturing specification provides the detailed instructions and technical data needed to actually make the product.

In simple terms, the design specification is the "what" and "why," and the manufacturing specification is the "how."

Design Specification

A design specification is a document created at the beginning of the design process.1 It acts as a set of rules and a checklist for the designer, ensuring the final product meets the needs of the client and user.2 It is focused on the end product and its performance, aesthetics, and function, but not on the specific processes used to make it.3

Examples of criteria found in a design specification:

• Aesthetics: "The product must have a modern, sleek appearance with a matte black finish."

• Function: "The product must be able to hold 5 kilograms of weight."

• Target Market: "The product is for children aged 3-5 years old."4

• Ergonomics: "The handle must be comfortable for an average adult hand to grip."

• Safety: "The product must not have any sharp edges or small parts that can be swallowed."

• Cost: "The final product must be able to retail for less than $20."

Manufacturing Specification

A manufacturing specification is created after the final design has been chosen and refined. It is a technical blueprint intended for the factory or workshop, providing all the precise details required for production. This document leaves no room for interpretation; it specifies every step and component to ensure a consistent, repeatable outcome.5

Examples of criteria found in a manufacturing specification:

• Materials: "Use 3mm thick 304-grade stainless steel sheet."

• Dimensions: "The hole for the bolt must be 6mm in diameter with a tolerance of +/- 0.1mm."

• Processes: "Laser cut the main body, then use a CNC press brake to fold the sides to a 90-degree angle."

• Assembly: "Attach component A to component B using two M6 stainless steel machine screws, tightened to 10 Nm."

• Finish: "Powder coat the entire unit using RAL 9005 (Jet Black) with a matte finish."

• Quality Control: "Check every 10th unit for correct dimensions using digital calipers."

Continuous production is when production runs 24 hours a day, 7 days a week because there is always a need for the product and stopping production would cause problems for consumers or industry. Milk, water, electricity, newspapers, bread and oil are all examples of products continuously produced. Again, the materials to be used and the expensive machinery required would need to be considered.

computer integraded manufacturing

Principle of Computer Integrated Manufacturing (CIM)

Computer Integrated Manufacturing (CIM) is the use of computer systems to control and manage the entire manufacturing process. Its fundamental principle is the integration of all manufacturing operations—from product design to shipping and delivery—into a single, unified system managed by computer technology. This creates a seamless flow of information and automation across the entire factory.

• Integration of Systems: CIM connects various standalone systems, such as CAD (Computer-Aided Design), CAM (Computer-Aided Manufacturing), and MRP (Materials Requirement Planning), into one coherent network. This eliminates manual data transfer and potential errors.

• Automation: A key component is the high level of automation in both the physical production line (e.g., robotics, CNC machines) and the administrative tasks (e.g., inventory tracking, quality control reporting).

• Data Sharing: Real-time data is collected and shared across all departments. This enables management to make informed decisions quickly, and allows for immediate adjustments to be made to the production process.

• Total Systems Approach: CIM treats the entire factory as a single, interdependent system. Changes in one area, such as a design modification, are automatically communicated and managed by the systems in other areas, such as tooling and production.

Advantages of Computer Integrated Manufacturing

• Improved Quality: Automation and real-time data monitoring reduce human error, leading to a higher consistency and quality of products.

• Increased Productivity: The seamless flow of information and automated processes significantly reduce production time, increase efficiency, and allow for a much higher output.

• Greater Flexibility: While in-line assembly is rigid, a CIM system can be reprogrammed to produce different product variations or entirely new products with relative ease, enabling a business to respond more quickly to market changes.

• Reduced Labour Costs: The high degree of automation reduces the need for manual labour, which can lead to lower operational costs in the long term.

Disadvantages of Computer Integrated Manufacturing

• Very High Initial Investment: Implementing a CIM system requires a significant capital outlay for new machinery, software, and IT infrastructure. This makes it an expensive option, particularly for smaller businesses.

• Dependence on Technology: The entire manufacturing process becomes reliant on the computer systems. A system failure or software bug can bring the entire production line to a halt, leading to major disruption.

• Complexity of Implementation: Integrating all the different computer systems and training staff to use them is a complex and time-consuming process. It often requires specialised technical skills and can face resistance from employees.

• Security Risks: Since the entire system is networked, it is vulnerable to cyber threats, data breaches, and other security risks that could compromise sensitive information or disrupt production.

Concurrent Engineering

Principle of Concurrent Engineering

Concurrent engineering, often referred to as simultaneous engineering, is a product development methodology in which different stages of the process, such as design, manufacturing, and support, are conducted in parallel rather than sequentially. The core principle is to integrate all aspects of a product's lifecycle from the very beginning, with the goal of reducing development time, improving quality, and lowering costs.

• Integrated Teams: The process relies on multi-disciplinary teams that include members from all relevant departments (e.g., design, manufacturing, marketing, logistics). This collaboration from the outset ensures all perspectives are considered early on.

• Parallel Processes: Unlike the traditional "over-the-wall" approach where one team finishes a task before handing it to the next, concurrent engineering allows multiple tasks to be performed at the same time. This significantly shortens the overall development timeline.

• Early Issue Identification: By involving manufacturing and logistics experts early in the design phase, potential problems related to production or supply chain can be identified and resolved before they become costly to fix.

• Iterative Design: The process is iterative, with continuous feedback loops between the different teams. This allows for rapid adjustments and improvements to the product design.

Advantages of Concurrent Engineering

• Reduced Development Time: By working on tasks in parallel, the total time from concept to market is significantly shortened, providing a key competitive advantage.

• Improved Product Quality: Early and continuous feedback from all stakeholders helps to identify and eliminate flaws, leading to a higher-quality final product that is easier to manufacture and maintain.

• Cost Reduction: Although the initial investment in team coordination may be higher, the long-term costs are often reduced by avoiding expensive redesigns, production delays, and rework.

• Enhanced Communication: The integrated team structure fosters better communication and collaboration between departments, breaking down traditional organisational silos.

Disadvantages of Concurrent Engineering

• Increased Complexity: Managing multiple parallel tasks and coordinating a diverse team can be highly complex and requires sophisticated project management tools and skills.

• Higher Initial Cost: Setting up a concurrent engineering system can be expensive, requiring investment in training, collaborative software, and the time of multiple experts early in the process.

• Potential for Conflict: The close collaboration required can lead to personality conflicts or disagreements between team members from different departments who may have competing priorities.

• Difficulty in Control: The non-linear nature of the process can make it harder for management to track progress and maintain control, as traditional milestones are blurred.

cell production

Principle of Cell Production

Cell production, also known as cellular manufacturing, is a lean manufacturing method that groups machinery, equipment, and people into a "cell" to produce a complete part or product family. The principle is to move away from a traditional linear assembly line and organize production around a product's flow.

• Group Technology: The core principle is based on group technology, which identifies and groups parts with similar characteristics (shape, size, or manufacturing process) into "part families."

• Self-Contained Cells: Each cell is a mini-factory, containing all the necessary machines and cross-trained workers to complete a family of products from start to finish. This contrasts with a traditional layout where machines are grouped by function (e.g., all lathes in one department, all mills in another).

• Continuous Flow: The layout is designed to facilitate a smooth, one-piece flow of materials and products through the cell, minimizing waste and transportation. Common layouts include U-shaped, L-shaped, and straight lines, with the U-shape being popular for its efficiency and ease of communication among workers.

• Worker Empowerment: Workers within a cell are often multi-skilled and empowered to manage their own tasks, identify inefficiencies, and contribute to continuous improvement (Kaizen). This fosters a sense of ownership and accountability.

Advantages of Cell Production

• Reduced Waste: Minimizes non-value-added activities such as material handling, transportation, and waiting time. This leads to less work-in-progress (WIP) inventory.

• Improved Quality: The close proximity of workers and processes creates an immediate feedback loop. Defects are identified and addressed quickly, which reduces rework and improves the overall quality of the product.

• Shorter Lead Times: By eliminating waiting and transport between departments, the time from raw material to finished product is significantly reduced.

• Increased Flexibility: Cells can be easily reconfigured or created to adapt to changes in product demand or to introduce new product variants. This makes the system highly responsive to market changes.

• Enhanced Worker Morale: Workers have more autonomy and can see the final product of their labor, which leads to a greater sense of achievement and job satisfaction. Cross-training also provides skill development.

Disadvantages of Cell Production

• High Initial Setup Cost: Implementing cellular manufacturing can be expensive and time-consuming. It may require rearranging a factory's entire layout and purchasing "right-sized" equipment to fit within the cells.

• Vulnerability to Bottlenecks: If a single machine within a cell breaks down, the entire cell's production can halt. This makes the system more susceptible to disruptions compared to a traditional layout with redundant machinery.

• Training Requirements: Workers need to be extensively cross-trained to perform multiple tasks within a cell, which can be an added cost and challenge for companies.

• Potential for Conflict: The close-knit nature of the work cell can lead to personality conflicts among team members, especially if teams are not equally productive or if there are delays.

• Limited to Specific Products: Cellular manufacturing is most effective for medium-volume production of "families" of products. It may not be suitable for low-volume, high-mix production or for very high-volume, single-product manufacturing.

In-line assembly

Principle of In-Line Assembly

In-line assembly, also known as flow production or mass production, is a manufacturing method characterised by a sequential and standardised process. The product moves along a line, with each workstation or worker adding a component or performing a specific task. This approach is designed for high-volume manufacturing of a single, uniform product.

• Standardisation: The core principle is based on the production of a single, identical product. This allows for the optimisation of every step and the use of highly specialised machinery.

• Sequential Layout: The production process is arranged in a linear or U-shaped sequence. The product moves from one workstation to the next, with each station performing a specific operation in a fixed order.

• Specialisation of Labour: Workers are highly specialised, performing one or a very small number of repetitive tasks. This minimises the training required and increases the speed of each task.

• Economies of Scale: The high volume of production allows for the cost of machinery and labour to be spread across many units, leading to a very low cost per unit.

Advantages of In-Line Assembly

• High Production Volume: The system is optimised for a single product, allowing for extremely high output rates and meeting large-scale market demand.

• Low Unit Cost: Due to economies of scale and efficient, repetitive processes, the cost of producing each individual unit is very low.

• Minimal Training: As each worker performs a simple, repetitive task, the time and cost associated with training are significantly reduced.

• High Machine Utilisation: Specialised machines are often in continuous use, which maximises their efficiency and return on investment.

Disadvantages of In-Line Assembly

• Lack of Flexibility: The linear layout is difficult and costly to reconfigure. It is not well-suited for producing a variety of products or adapting to changes in product design.

• High Initial Setup Cost: The initial investment required for the machinery and factory layout of an in-line assembly system is substantial.

• Worker Dissatisfaction: The repetitive and monotonous nature of the work can lead to low job satisfaction, boredom, and high employee turnover.

• Vulnerability to Downtime: A single machine breakdown or bottleneck in one part of the line can cause a halt in production for the entire line, leading to significant delays and losses.

• High Inventory Requirements: To avoid halting the entire line, buffer stocks are often required, which can increase inventory costs and lead to waste.

Efficient use of materials

When setting out to design and manufacture a product, deciding which material to use can be straightforward since the specification for the part may preclude other options. For example a twist drill must be made from a high speed steel if it is to drill into softer materials and a hinged lid for a freezer food container would be made from PP as it is the only polymer that can withstand freezing temperatures!

However, cheaper versions may be found, but this might affect the product quality and increase the likelihood of failure!

The amount of material used is also a key consideration and advances in FEA and CAD engineering may lead to a product being improved while actually using less material.

Manufacturing processes which increase accuracy and reduce waste

The design of a manufacturing system, including jigs and formers, to be used to make a product in quantity.

Some of the most important measuring tools were dealt with at the start of this unit, but in some cases, accuracy and speed can be improved and potential human errors eliminated by using jigs, fixtures and templates.

This is particularly appropriate when scales of production are greater than one or two products and especially in batch and mass produced items.

The use of non-contact measuring devices such as laser based technologies are becoming more common and can be beneficial when greater accuracy is needed or it is difficult to handle the material due to size, access or safety reasons.