Section O
Design
Don't be buffaloed by experts and elites. Experts often possess more data than judgment. Elites can become so inbred that they produce hemophiliacs who bleed to death as soon as they are cut by the real world.
General Colin Powell
The design phase is the link between the owner's business development process during the feasibility stage and the production, manufacturing, fabrication, or construction phase. More importantly, however, it is the link between the owner's concept for making money and the realization of the benefits during the operational phase.
The danger is that because of the remoteness of the home office from the physical activities of the project, people often start to believe that they are producing an end product in its own right. This is, of course, not the case ‐ the home office is providing a service to the later phases of the project. It is the construction people who are actually producing the end product. Further, as the people who have to interpret the design, they need to be involved in these earlier definition stages. Additionally, the people in the home office need to constantly bear in mind the fact that small mistakes in the early paper development phases can cause a vast amount of work in the later physical execution stages.4
1 Getting Organized
1.1
Get the right people; see Section D Mobilization, paragraphs 1.1 to 1.5.
1.2
Line managers may want to introduce new systems and ways of doing things so that the company can develop and progress. Think about it and work out how you can cooperate.
1.3
Any contract that has been awarded after a demanding competitive tendering process will need closer attention than normal. Make the team aware of this.
1.4
Review and approve design:
- Objectives and plans
- Organization
- Staffing
- Budgets
- Schedules.
1.5
Clarify the need for any outside design services (other divisions, design subcontractors, consultants, design packages, and so on).
1.5.1
Subcontract design work to cheaper local offices to perform activities requiring site information, for example, steam tracing.
1.6
Arrange for any necessary design data to be obtained from the project location (site), the client, or the owner.
1.7
Arrange for any necessary visits to the project site.
2 Reviewing the Design
2.1
Think and do are watch words for a design group under pressure. There is a tendency to do and then think about it. Think and then do means: ‘do it once and do it right.’
2.2
Obtain and review any process/design packages supplied by the client, owner, and or others. Ensure that they are in line with any statements made in the contract.
2.2.1
Carry out the detailed review of the basic design package with:
- Fabrication/installation/construction group: to make decisions on the project breakdown for subcontractors, modules and pre‐assembly.
- Commissioning/start‐up group: to ensure the plant will start up efficiently. Agree on testing tolerances as soon as possible. See Section S, paragraph 1.2. See also Part III, Section E, paragraph 2.24.
- Operations personnel: check for ease of operation and that the system or plant includes all the features they require.
- Maintenance personnel: check for ease of maintenance.
- Safety group: check that the plant complies with all statutory requirements.
- Hazard analysis group/HAZOP: carry out a review of the process and instrument diagrams.
- Reliability group: obtain their input to the design and maintenance.
- Environmental specialists: check for conformance with the appropriate standards.
2.3
Ensure that client approval requirements are clearly defined and complied with.
2.4
Define the safety philosophy for the design. Design safety is 90 per cent common sense and experience, the remaining 10 per cent being special expertise. Make sure that this special expertise is used because 10 per cent can make a difference in safety matters.
2.5
Utilise functional design management to resolve technical problems. If you have doubts about a particular piece of work, get it checked out by the functional manager involved. You cannot be an expert on every aspect of design and, in any case, you do not have the time to get involved. If in doubt, get it checked. If in serious doubt, get the functional manager to confirm their approval of the design in writing.
2.6
Check the interfaces for the design sequence. Process systems get broken down to geographical areas, these are broken down again into disciplines and then to specific deliverables.
2.7
Analyse the work process and decide on the systems that are to be used for production of work.
2.8
Check contractual or financing constraints on purchasing before decisions are made about material requisitions.
2.9
If you are going to cut corners (in order to save money) talk to the quality assurance people on how you can do it without losing your quality accreditation.
3 Some Specific Design Ideas
3.1
Limit the number of vendor prints to a minimum – the essentials. Improve the turnaround of vendor prints. Time spent correctly indexing and cross‐referencing vendor prints will save time later on.
3.2
Some design reminders:
- List the equipment shown on an engineering flow diagram on the far right‐hand side of the drawing. Thus the EFDs can quickly be flicked through in order to locate specific equipment.
- Have the same scales for the piping plans and the electrical plans so that they can be overlaid to check for interferences.
- Check that the primary voltage matches the electrical area classifications for:
- All vendor‐supplied instruments and control valves.
- Door openers and ventilation fans.
- Make sure that the instruments listed on the engineering flow diagrams have been included prior to purchasing equipment.
- Standardise as much as possible.
- Design to minimise scaffolding.
- Do not put firm dimensions on small‐bore piping around equipment that has not yet been installed. Note; small‐bore piping is prone to being underestimated.
- Don't over‐engineer large equipment packages.
- On tall structures, arrange for pipe and cable trays to be on the inside of the structure and, where possible, adjacent to the stairwell. This saves scaffolding and crane erection costs on site.
- Pay particular attention to ‘undergrounds’. Look at piping crossings and ask: “How can this deep and costly excavation be avoided?”
- Allow for fireproofing thickness on structural steel when laying out pipework.
- Before you commit to a design change, check what stage the vendors are at. Can you make the change without disrupting them?
4 Construction Issues
4.1
Arrange for rigorous constructability reviews. Involve industrial relations in the constructability reviews to check for trade demarcations.
4.2
Optimise the extent of engineering. Only do what construction needs to build the project.
4.3
Make sure that construction defines the preferred sequence of equipment deliveries so that design and procurement can take the necessary action to achieve it.
4.4
Review the questions in Section R, if subcontracting any design work is proposed.
4.5
Allow/arrange for engineering support on site.