Engineering Process
Overview of PSI’s engineering workflow from proposal through production release.
Engineering Departments
| Dept | Code | Responsibility |
|---|---|---|
| Mechanical Engineering | 110 | Machine design, drawings, specifications |
| Controls Engineering | 111 | PLC programming, electrical design, automation |
| Proposal Engineering | 115 | Customer quotes, technical sales support |
Design Workflow
Phase 1: Proposal
- Customer RFQ received
- Proposal Engineering develops concept
- High-level design and specifications
- Quote generated
- Customer approval
Phase 2: Engineering Design
- Kickoff: Project assigned to engineers
- Concept Design: Overall machine layout
- Detail Design: Individual component design
- Drawing Release: Drawings approved for production
- BOM Creation: Bill of Materials finalized
Phase 3: Design Support
During manufacturing:
- Answer shop floor questions
- Process ECNs for design changes
- Support procurement on vendor specs
- Assist MVI with testing issues
Drawing System
SolidWorks PDM
All engineering drawings are managed in SolidWorks PDM (Product Data Management):
- Version control
- Approval workflows
- Check-in/check-out
- Revision history
Drawing Number Conventions
PSI drawing numbers follow patterns like:
1234-567-890- Assembly drawings- Part-specific numbering based on GTCode level
Drawing States
| State | Meaning |
|---|---|
| Work in Progress | Being designed |
| Released | Approved for production |
| Obsolete | No longer valid |
BOM Structure
Hierarchy (GTCode Levels)
FACILITY (Complete Machine)
├── ASSEMBLY (Major assembled components)
│ ├── MODULE (Reusable functional units)
│ │ └── PHYS. (Physical parts - lowest design unit)
│ └── PHYS.
└── ASSEMBLY
└── ...
BOM Fields
| Field | Description |
|---|---|
| Level | Depth in hierarchy (0 = top) |
| Part Number | Unique identifier |
| Description | Part description |
| Qty | Quantity required |
| MRP Type | P=Purchased, M=Manufactured |
See BOM in terminology.
ECN Process
What is an ECN?
An Engineering Change Notice is a formal document authorizing changes to engineering drawings or specifications.
When Required
- Design changes affecting fit, form, or function
- Dimension changes beyond tolerance adjustments
- Material substitutions
- Assembly method changes
ECN Workflow
┌──────────────┐ ┌──────────────┐ ┌──────────────┐
│ Initiated │────▶│ Approved │────▶│ Implemented │
│ (Change need)│ │ (Reviewed) │ │ (Released) │
└──────────────┘ └──────────────┘ └──────────────┘
│ │ │
▼ ▼ ▼
Document Signatures Drawings
change reason obtained updated
ECN Impact Assessment
- Affected drawings identified
- In-process parts evaluated
- Inventory impact assessed
- Cost impact calculated
Design Reuse
Philosophy
PSI designs custom machines but reuses proven components where possible:
Reuse Metrics
| Metric | Typical Value |
|---|---|
| PHYS. level reuse rate | ~82% |
| First-time part issues | 1.09x higher cost |
Benefits
- Faster design time
- Known quality characteristics
- Reduced risk
- Lower cost
See Design Reuse Analysis for data.
Design Reviews
Types of Reviews
| Review | Timing | Focus |
|---|---|---|
| Concept Review | Early design | Overall approach |
| Detail Review | Mid-design | Specific components |
| Release Review | Pre-release | Final check |
Checklist Items
- Interference checks completed
- Tolerances analyzed
- Materials specified
- Standard parts used where possible
- Assembly sequence considered
- Service access provided
Quality Integration
Redbook Linkage
When engineering issues cause redbooks:
- Drawing errors → Typos, missing dimensions
- Design function → Component undersized, interference
- Information gap → Requirements unclear
Prevention Methods
From Deep Dive analysis:
- Design review checklists
- Peer review process
- Interference checking tools
- Customer requirements clarification
Related Pages
- Terminology - Engineering terms
- Quality Process - ECN/NCN integration
- Manufacturing Process - Production handoff
- Data Brain - Data sources and systems
Last updated: February 2025