Table 4.4 Approximate Checklist Analysis Time Requirements

DOE-HDBK-1100-2004

Table 4.4 Approximate Checklist Analysis Time Requirements

SCOPE

PREPARATION

EVALUATION

DOCUMENTATION

Simple/Small

System

2 to 4 hours

4 to 8 hours

Complex/Large Process

1 to 3 days

3 to 5 days

2 to 4 days

4.1.4 Limitations of Checklist Analysis

When derived from handbooks or similar sources, many entries in a checklist may not be

applicable to the process being studied. In other cases, process hazards may be so

unusual they are not in standard checklists. Thus, it may be difficult to assure that all

hazards have been analyzed. Also, checklists may indicate that hazards exist, but not

what accident scenarios are associated with them.

4.1.5 Example Checklist Analyses

Simplified checklist analyses for the two example processes in Section 4.0 are shown in

Tables 4.5 and 4.6. The same checklist was used for both processes.

4.2

What-If Analysis

The purpose of a what-if analysis is to identify hazards, hazardous situations, or specific

accident events that could produce an undesirable consequence. The what-if analysis is

described in detail in Guidelines for Hazard Evaluation Procedures (CCPS, 1992).

What-if analysis involves the examination of possible deviations from the design,

construction, modification, or operating intent of a process. It can be used to examine

virtually any aspect of facility design or operation. Because it is so flexible, it can be

performed at any stage in the life of a process using whatever process information and

knowledge is available.

4.2.1 Description of the Method

The what-if analysis is a creative, brainstorming examination of a process or operation

conducted by a group of experienced individuals able to ask questions or voice concerns

about undesired events. It is not as inherently structured as some other methods, such as

the hazard and operability (HAZOP) study or a failure mode and effects analysis

(FMEA). Rather, it requires the analysts to adapt the basic concept to the specific

application.