Establishing Target Specifications - Product Specifications | ME 2024, Study notes of Mechanical Engineering

Download Establishing Target Specifications - Product Specifications | ME 2024 and more Study notes Mechanical Engineering in PDF only on Docsity! Chapter 6 – Product Specifications 1. Establishing Target Specifications a. Step 1: Prepare the list of metrics i. The most useful metrics are those that reflect as directly as possible the degree to which the product satisfies the customer needs ii. Needs-metrics matrix 1. Rows correspond to the customer needs 2. Columns correspond to the metrics 3. A mark in a cell means that the need and the metric associated with the product satisfies the customer need 4. Guidelines for constructing the list of metrics a. Metrics should be complete b. Metrics should be dependent, not independent of the variables c. Metrics should be practical d. Some needs cannot easily be translated into quantifiable metrics e. The metrics should include the popular criteria for comparison in the marketplace b. Step 2: Collect competitive benchmarking information i. The detailed position of a team’s product relative to existing products should be agreed on between the team members ii. A competitive benchmarking chart is used to accomplish this task c. Step 3: Set ideal and marginally acceptable target values i. Two types of target value 1. Ideal value a. Best result the team could hope for 2. Marginally acceptable value a. Value of the metric that would just barely make the product commercially viable ii. Five ways to express the values of the metrics 1. At least X 2. At most X 3. Between X and Y 4. Exactly X 5. A set of discrete values d. Step 4: Reflect on the results and the process i. Once the targets have been set, the team can proceed to generate solution concepts 2. Setting the Final Specifications a. Difficult because of trade-offs i. Frequently occur between different technical performance metrics ii. Almost always occur between technical performance metrics and cost b. Five-step process i. Develop technical models of the product 1. Technical model = a tool for predicting the values of the metrics for a particular set of design decisions a. Almost always unique to a particular product concept