Design: a quality management perspective

Summary

This article considers quality management aspects for three key stages of designing for construction. Consecutively, they are:

Concept > Preliminary > Detail Design

The techniques for quality assurance used tend to be similar at each stage. They are therefore listed here as an overview:

Design risk assessment
Design review
Document & drawing control
Calculations & computer modelling control
Checking & approval
Design change control
Post-project review (lessons learned)

Primarily, it is the scope of the application of each technique that can vary between design stages, eg as the design increases in complexity, a more in-depth approach to both design review and checking & approval is required.

For the purposes of this article, two or three of the techniques are considered for each design stage but their application is not limited to any stage.

Concept design

Concept design is an early phase of the design process often used to determine the feasibility of options in order to arrive at solutions which meet the client’s requirements. This could range from proposing refurbishment of an existing asset to demolition and constructing anew.

For the development of its estate, Imperial College London [1] describes concept design as the stage at which, ‘The design team shall explore all design options/proposals that could meet the requirements of the design brief and develop them into concept design including outline proposals for structural design, services systems, outline specifications, and preliminary cost plan along with environmental, energy, ecology, access or other project strategies‘.

Requirements that Imperial College considers at this stage include architectural standards, CAD strategy, mechanical & electrical components and building engineering services.

The Institute for Transportation and Development Policy (ITDP) Bus Rapid Transit (BRT) Planning Guide, 4^th Edition [2] says that the output of concept design stage, is that the designer, ‘should provide a sufficient level of detail so that decision makers may properly evaluate the cost functionality and aesthetics of the proposed system’.

Outputs from concept design stage can include sketches and models.

Design risk sssessment

ISO 9001:2015 [6], art 6.1.2 requires planning to address both risks and opportunities.

The design risk assessment tool involves identifying risks arising in the design, understanding who will be affected and determining appropriate measures to mitigate any significant risks that cannot be avoided. Design organisations tend to have their own bespoke templates which address the two key aspects of risk identification and mitigation. The Association for Project Safety [3] offers the ‘Pre construction phase design risk register’ template on its website at: https://www.aps.org.uk/supporting-example-documents-and-templates

In the UK, design risk assessment can be a useful tool in managing compliance with Construction design & management (CDM) regulations which is the subject of a separate article in this series.

The design risk assessment is normally developed through the full design process and submitted with the health & safety file to the contractor to be taken forward into the construction phase.

Furthermore, risk assessment in a similar way can be used to identify sustainability opportunities and environmental risks. Like health & safety, prevention of pollution in the environment is a legal requirement which is best considered from the very beginning in order to reach the most effective solutions as the output of design. While technically not a legal requirement, good sustainability analysis can bring not just environmental benefits to the project but offer cost savings as well, eg in achieving reduced energy consumption costs through specifying better insulation in buildings.

Design review

Imperial College London mandates that project design reviews shall be held during the concept design stage. These would be a feature of any designer’s management system at all design stages, as it is required by ISO 9001:2015 [6], art 8.2.3 (Review of the requirements for products and services).

Types of review include: preliminary design review (eg at 30-50% complete), single discipline review (SDR) and inter-disciplinary review (IDR).

Key elements of a design review can include:

The reviewer appointed should be a competent and experienced design engineer
The reviewer should be independent of the project team, if possible, or at least not connected to the day-to-day design activity. This is so that they bring a fresh pair of eyes to the review
Carry out the review at critical stages in the design process; these should be defined in the quality plan
Verify that the design being developed is consistent with the design objectives established
Review drawings, calculations, test requirements etc to identify and correct potential problems (including in the deliverables)
Standardised approach using an electronic form to provide a template for recording the findings of the review, their acceptance or otherwise by the project principal and the improvement actions taken as a result by the project manager

Preliminary design

This is high-level design that takes forward the chosen option(s) in the concept design to create the framework on which to build the later detail design. Preliminary design is about determining how the overall project will be configured for construction.

At this stage, the design team will also do field investigations, eg geotechnical. They will also study the layout of the areas concerned, including building systems and statutory undertakings (location of power cables, broadband lines, drainage, sewers etc). They are seeking to establish the potential impact of the presence of these services and determine how the project will be designed to accommodate them.

Environmental surveys of affected habitat are also conducted by ecologists at this stage.

This aspect of the design process is typically required on highways and railways projects.

Outputs from preliminary design stage can include schematics, diagrams and layouts.

Document & drawing control

ISO 9001:2015 [6], art 7.5.3 requires control of documented information. This means project information generally such as documents, drawings and calculations.

It is important that all documentation on the project is controlled so that the correct version is used by the intended recipient. This includes documents and drawings received, eg from the client, as well as the ones the design team produces. Registers are used in this case.

Incoming and outgoing document / drawing registers typically record:

Originator (incoming information)
Date item received or issued
Title of the item
A unique reference for the document, drawing etc (facilitates traceability)
Revision status
Distribution
Purpose of issue (eg ‘For information’)
Folder location assigned (Incoming)
The project manager’s review and approval of all incoming information for use on the project

The outgoing register can also double as the transmittal document.

System software is available for records management such as ‘MS SharePoint’, ‘Livelink’ and ‘Bentley’. A key security feature is the flexibility to be able to restrict access to folders to only those members of the project team who need all or just certain information.

There will be a retention period specified in the contract or by the design company or stipulated in law (eg ‘As built’ drawings should be kept for 50 years).

Calculations & computer modelling control

For calculations, a ‘Calculations cover sheet’ is commonly used to administer each set. It serves to provide a records trail of the development of the calculations from the inputs, through checking & approval to where the outputs will ultimately be used (eg refer to drawing numbers).

Where more than one set of calculations is performed, they are registered using a simple ‘Calculations index’.

The principles of competency and experience in the topic in question (set out in design review above) also apply for those checking & approving calculations.

It is important that the calculations records show the pass/fail Criteria to demonstrate the results are satisfactory.

Calculations should be saved with documents and drawings in the electronic records management system so that their availability for reference is also preserved.

Computer modelling and demand forecasting can be foremost in customers’ minds in that mistakes can be expensive for them. For example, should the demand forecasted for the public use of a toll road as designed exceed the actual experience in operation, this would leave a gap in the highway operator’s financial expectations which had been derived from those forecasts.

The applicable quality assurance principles can be distilled to three activities:

Carry out a ‘peer assist’ at the beginning of the project where a more experienced modeller sits down with the project team and mentors the planning and direction of the work
Produce a checking plan
Review that the work is being carried out in accordance with that checking plan

Detail design

Detail design provides definition for the project. IEEE [5], the technical professional organisation for the advancement of technology, describes detail design as, ‘The process of refining and expanding the preliminary design phase of a system or component to the extent that the design is sufficiently complete to be implemented’.

It may consist of procurement of materials as well which must be specified and can include writing test plans and assessing prototypes.

It is at this stage that the full cost of the project is identified.

This approach is used on major infrastructure projects.

Outputs from detail design stage can include 2D and 3D models, drawings, plans (including procurement plans), specifications and estimates.

Checking & approval

Checking & approval has been an engineering discipline for thousands of years. In the past eight decades it has become a requirement of management systems standards, leading to ISO 9001 today.

ISO 9001:2015 [6], art 8.3.4 requires design and development controls including verification and validation activities.

All information produced must be verified for its suitability for the intended purpose before it is issued. In essence, the checker(s) must have the competence to check the design output (documents, drawings, calculations specifications etc) and thereafter the approver satisfies themselves that an effective check was performed.

Checkers and approvers should be nominated in the quality plan for the project. They should have been assessed as competent for their role. Typically, in an engineering discipline, checkers can be of chartered status with five years or more experience. The approver is usually more senior with greater experience.

The scope of checking to be employed for each of the different types of project deliverable should also be described in the quality plan.

Contents for a quality plan can be found in ISO 10005:2005 – Quality management systems – Guidelines for quality plans [7].

Many records management systems now have automated processes, called ‘Workflows’, for facilitating the checking & approval process.

Design change control

ISO 9001:2015 [6] art 8.3.6 requires design and development changes to be controlled, to record what the changes are and how they came about (ie through design review). It is especially the impact the change is expected to have that must be understood.

Where the need for a change is identified by a member of the design team, the design lead determines any necessary action and ensures that the reason for the change is recorded. Internal authorization should be obtained, eg from the project principal, before formal submission of the change to the client, eg in the form of an ‘Early warning notice’.

There must also be records of the actions taken to prevent adverse impacts. Analysis for this can include use of the design risk assessment (see item 1 above).

Where a design or scope change is required in response to an alteration in the client’s requirements, the design lead must obtain a written instruction from the client, eg by way of a ‘Compensation event’ notification.

Any design change resulting in a variation to the project budget needs to be reported by the project manager to the client for their approval. This is the case whether the change is instigated by the project team or one of its partners or sub-consultants.

Post-project review (lessons learned)

ISO 9001:2015 [6], art 10.1 requires the pursuit of improvement, eg in products and services.

As the project completes, there is unlikely to be an opportunity to make significant changes to it now but lessons can be identified for future projects; not just ‘Things gone wrong’ but success factors as well.

A database to record these ideas at all stages of the project lifecycle is beneficial. The information stored can then be searched at any time when inspiration is sought but this is particularly effective before starting new projects. Studying what has gone before can save time and money in setting the direction of the new project.

Design-related topics covered in a post-project review include assessment of the technical content of the solution, resourcing (skills available), problems encountered as well as innovation created.

Nevertheless, this can be condensed into two questions: