Definition and Measurement of Engineering/Design Deliverable Quality (Best Practice)

RT-320 Topic Summary
RT 320


Defects in engineering/design deliverables negatively affect project performance in terms of cost, schedule, and safety, by causing significant amounts of rework in the design and/or construction phases. RT-320 offers capital project teams key guidance on assessing both the design quality and the design completeness of the most problematic engineering/design deliverables.  
RT-320 took a bottom-up, priority-driven approach to understanding design quality defects, impacts, causes, and methods of measuring design quality. The team began by identifying the 11 most problematic deliverables and the 73 most common and significant defects associated with these deliverables. The research team then identified 349 causal factors, from which were derived 118 leading and 23 lagging metrics. With additional insight from published literature and corporate practices, the team identified 266 completeness checklist items for the 11 most problematic deliverables. Finally, RT-320 developed two implementation tools: the Design Deliverable Quality Assessment (DDQA) tool and the Completeness of Design Deliverable Checklist (CDDC) tool. IR320-2, Tools for Enhancing the Quality of Problematic Design Deliverables, presents the major findings of this research, the highlights of the two implementation tools, the inputs and outputs of the tools, and the roles and responsibilities of potential users. 

Key Findings and Implementation Tools

1 : Design Quality Essentials

Based on prior published literature, RT-320 defined design deliverable quality in terms of their completeness, correctness, and timeliness.

Reference: (RS320-1)

2 : Relative Frequency of Deliverable Quality Problems per Deliverable Type

RT-320 surveyed industry to identify the most problematic deliverables in terms of quality (N=67). The RT found similarities in the relative frequency of design quality problems encountered by owners (X-axis value) and contractors (Y-axis value).
Reference: (RS320-1)

3 : The 11 Most Problematic Design Deliverables

No. Deliverable
1 FEED Validation Deliverables
2 Level 3 Baseline Schedule
3 Constructability Inputs
4 P&IDs
5 Equipment Specifications & Data Sheets
6 Maintainability Inputs
7 Vendor Data
8 3D Model & Clash Detection
9 Piping Routing & Isometrics
10 Nozzles, Ladders, & Platforms for Towers/Vessels/Tanks
11 Misc. Pipe Support Drawings
From the scatter plot shown in Key Finding #2, RT-320 concluded that deliverables are “problematic” if quality problem frequency is between “Sometimes (3.0)” and “Too Often (5.0).”
Reference: (RS320-1)

4 : Analysis of 73 Significant Design Deliverable Defects (Deliverable Defects List)

The industry survey (N=36) identified 798 common defects associated with the 11 problematic deliverables. RT-320 consolidated and aggregated these common defects, developing a list of 73 significant design deliverable defects (6.63 defects per deliverable on average). Among the 73 defects, 24 percent pertain to completeness, 60 percent pertain to correctness, and 16 percent pertain to timeliness.