Case Study: Pilot Production of a Medical Device Enclosure

Project Background

A medical device company was preparing for pilot builds of a handheld diagnostic unit before formal market launch. The product had already passed early prototype review, but the team still needed a stable enclosure solution for small-batch assembly, internal validation, and customer-facing demonstrations. The enclosure included multiple visible plastic housing parts, internal mounting features, alignment interfaces, and cosmetic exterior surfaces that needed to look close to a production-ready product.

At this stage, the customer was no longer looking for simple appearance prototypes. The main need was a controlled bridge between prototype development and future production tooling, with enough flexibility to refine remaining details without delaying the pilot schedule.

Customer Requirements

The customer’s requirements were specific, emphasizing production-like quality and efficiency for their critical pilot builds.

production-like enclosure parts for pilot assembly
good cosmetic consistency across visible exterior surfaces
stable fit between upper and lower housing sections
repeatable screw-boss and internal mounting alignment
manageable tooling cost before full production release
short lead time to support pilot build timing
inspection records for key assembly-related dimensions

High-tech robots assembling a car in a modern factory setting, showcasing automation.

Engineering Challenges

The main engineering challenge was not simply making the plastic parts. It was making them stable enough for pilot use, with critical cosmetic and functional requirements.

Risk Areas (with bullet points and brief explanations):
- Visible cosmetic faces: Could not tolerate obvious sink or surface inconsistency.
- Multiple internal bosses and mounting features: Directly affected PCB alignment.
- Joining edges between housing halves: Gap consistency was crucial for appearance and fit.
- Dimensional sensitivity: Around fastening points and locator features.
- Limited schedule margin: Before pilot assembly started.
Process-Selection Challenge:
- Explanation of why CNC machining and full production tooling were not ideal.
- Emphasis on the need for a “middle path.”

Manufacturing Solution

EPOC recommended a rapid injection molding route using production-family plastic material and a tooling strategy designed for pilot and bridge-stage output rather than full long-run production.

DFM review before tooling release.
Review of wall thickness transitions and boss geometry.
Adjustment of selected cosmetic and structural features to reduce sink risk.
Confirmation of critical assembly-related dimensions on the drawing.
Pilot-oriented mold strategy to shorten T1 timing.
Molded sample review before stable batch release.

Process Controls

To keep the project under control, EPOC applied several key process controls from the outset, mitigating risks and ensuring project stability.

Numbered List of Controls:
1. DFM-based geometry review: Boss transitions, wall balance, and local mass concentration reviewed before tooling release.
2. CTQ feature identification: Key housing interfaces, screw-boss locations, and selected internal mounting dimensions treated as critical-to-quality.
3. Sample-stage validation before wider release: T1 samples used to verify fit, cosmetic condition, and assembly behavior.
4. Controlled communication loop: Engineering feedback, sample review, and approval decisions handled in a structured sequence.

Results & Metrics

Through strategic partnership and expert manufacturing, this project delivered tangible results that directly supported the customer’s market readiness.

T1 sample release within the pilot development window.
Pilot batch delivered in time for customer assembly planning.
Stable fit between major housing sections during pilot builds.
Improved cosmetic consistency after early DFM-led geometry adjustment.
Reduced risk of rework on PCB mounting and fastener alignment features.
Lower upfront tooling commitment compared with immediate production tooling release.