APPENDIX VI.     “WHAT-IF” HAZARD ANALYSIS

 

            Included in this appendix is information on how to conduct a “what-if” hazard analysis.  In particular, a form (Figure C-1) is included, and this form should be completed for each written report.  The purpose of this exercise is to teach you how to conduct a “what-if” risk assessment and also to ensure that we are aware of any safety concerns you may have about the experiments.  Safety concerns that arise during the course of the experiment should be immediately brought to the attention of one of the TAs and the Technical Instructors.

 

            The reference for the attached material is:

 

Handbook of Occupational Safety and Health, Second Edition, edited by Lou Diberardinis, “Chapter 6 Risk Assessment Techniques,” Thomas M. Dougherty, pp. 127-178, John Wiley and Sons, 1999.

 

What-If Analysis

 

A.        What-If Analysis Overview

 

            What –If Analysis is a structured brainstorming method of determining what things can go wrong and judging the likelihood and consequences of those situations occurring.  The answers to these questions form the basis for making judgments regarding the acceptability of those risks and determining a recommended course of action for those risks judged to be unacceptable.  An experienced review team can effectively and productively discern major issues concerning a process or system.  Lead by an energetic and focused facilitator, each member of the review team participates in assessing what can go wrong based on their past experiences and knowledge of similar situations.

 

            Using an operating procedure and/or Piping and Instrument Diagram (P&ID), the team reviews the operation or process step utilizing a form similar to one illustrated in Figure C-1.  Team members usually include operating and maintenance personnel, design and/or operating engineers, specific skills as needed (chemist, structural engineer, radiation expert, etc.) and a safety representative.  At each step in the procedure or process, What-If questions are asked and answers generated.  To minimize the chances that potential problems are not overlooked, moving to recommendations is held until all of the potential hazards are identified.

 

            The review team then makes judgments regarding the likelihood and severity of the “What-If” answers.  If the risk indicated by those judgments is unacceptable then a recommendation is made by the team for further action.  The completed analysis is then summarized and prioritized, and responsibilities are assigned.


 

“What-If” Hazard Analysis

 

Division:

Desc. of Operation:

By:                    Date:

 

What If?

Answer

Likeli-

hood

Conse-

quences

Recommendations

 

 

 

 

 

 

 

 

 

 

 

Figure C-1.  What-If Analysis Form

 

B.            Getting Started – What’s Needed

 

            The first steps in performing an effective analysis include picking the boundaries of the review, involving the right individuals, and to have the right information.  The boundaries of the review may be a single piece of equipment, a collection of related equipment or an entire facility.  A narrow focus results in an analysis that is more detailed and explicit in defining the hazards and specific recommended controls.  As the review boundaries expand to include the equipment involved in a large complex process or even an entire facility the findings and recommendations become more overview in nature.  The boundaries can include the steps in the construction of the system under review, the steps involved in the operation of the equipment or facility or the steps required to maintain the equipment or facility.  A clear definition of the boundaries of the analysis starts the review off in an effective manner.

 

            Assembling an experienced, knowledgeable team is probably the single most important element in conducting a successful What-If analysis.  Individuals experienced in the design, operation, and servicing of similar equipment or facilities is essential.  Their knowledge of design standards, regulatory codes, past and potential operational errors as well as maintenance difficulties brings a practical reality to the review.  On the other hand, including new designers and new operators in the review team mix is an excellent learning opportunity for subjects that are not taught in design school or in operating classes.

 

            The next most important step is gathering the needed information.  One important way to gather information on an existing process or piece of equipment is for each review team member to visit and walk through the operation.  Videotapes of the operation or maintenance procedures or still photographs are important and often under utilized excellent sources of information.  Additionally, design documents, operational procedures, or maintenance procedures are essential information for the review team.  If these documents are not available, the first recommendation for the review team becomes clear.  Develop the supporting documentation!  Effective reviews cannot be conducted without up-to-date reliable documentation.  An experienced team can provide an overview analysis, but nuances to specific issues such as interlocks, pressure relief valves, or code requirements are not likely to be found.

 

 

C.            Conducting the Review – How’s it Done?

 

            Now that the team has had an opportunity to review the information package, the next step is conducting the analysis.  Generally, an experienced hazards review facilitator will lead the group through a series of “What-If” questions.  A focused, energetic and knowledgeable facilitator can keep the review moving productively and effectively.  A scribe is usually assigned to take notes of the review.  Recent advances in software as well as laptop computers can provide on-line data collection possibilities by the scribe.  That is, as hazards are identified, judgments made, and responsibilities assigned, the scribe can input the data and agreements live!  Scheduling more than four hours at a time can result in the team members losing energy and eager to finish the analysis rather than probing deeper.  Generally, in a well-designed system or well-operated system, the participants in the review will need to work hard to find major issues.  It is the job of the facilitator to keep the effort moving productively.

 

            1.   Developing the “What-If” Questions – Using the documents available and knowledge of the review team, “What-If” questions can be formulated around human errors, process upsets, and equipment failures.  These errors and failures can be considered during normal production operations, during construction, during maintenance activities, as well as during de-bugging situations.  The questions could address any of the following situations:

 

·       Failure to follow procedures or procedures followed incorrectly

·       Procedures incorrect or latest procedures not used

·       Operator inattentive or operator not trained

·       Procedures modified due to upset

·       Process conditions upsets

·       Equipment failure

·       Instrumentation miscalibrated

·       De-bugging errors

·       Utility failures such as power, steam, gas

·       External influences such as weather, vandalism, fire

·       Combination of events such as multiple equipment failures

 

            Experienced personnel are knowledgeable of past failures and likely sources of errors.  That experience should be used to generate “What-If” questions.

 

            For example, consider a chemical manufacturing process which includes the charging of a granular-like material from a 55-gallon drum to a 1000-gallon mix vessel containing a highly caustic liquid.  Some typical questions that could be generated are shown in Figure C-2 for illustration purposes.

 

            As the “What-If” questions are being generated, the facilitator should ensure that each member of the team has an opportunity to input potential errors or failures.  Determining the answer to each question as it is generated creates the danger of closing too soon on all possible upsets.  The facilitator needs to assess if the team has really looked at all of the possibilities before going to the next step of answering the questions.  Break up the analysis into smaller pieces if there is danger of just developing questions and not gaining the value of having them fresh in mind to answer those questions.

 

 

Division:  Chemical Ops

Desc. of Operation:  Manufacturing B Mix/Drum Charging Operations – Page 2 of 4

By:  Review Team Date 9/97

 

 

What If?

Answer

Likeli-

hood

Conse-

quences

Recommendations

1.  Granular powder is not freely flowing?

2.  Drum is mislabeled?

3.  Wrong powder in the drum?

4.  Drum hoist is not used?

5.  Two drums are added?

6.  Drum is misweighed?

7.  Drum hoist fails?

8.  Drum is corroded?

9.  Ventilation at mixing tank is not operating?

10.Granular powder becomes dusty?

11.Powder gets on operator’s skin?

12.Tank liquid level too high?

 

 

 

 

 

Figure C-2.  Example of Completed Step No. 1 What-If Analysis Form

 

            2.            Determining the Answers – After being assured that the review team has exhausted the most credible “What-If” scenarios, the facilitator then has the team answer the question,  What would be the result of that situation occurring?  For example, consider the following answers illustrated in Figure C-3 to the “What-If” questions in our previous example.

 

Division:  Chemical Ops

Desc. of Operation:  Manufacturing B Mix/Drum Charging Operations – Page 2 of 4

By:  Review Team Date 9/97

 

 

What If?

Answer

Likeli-

hood

Conse-

quences

Recommendations

1.  Granular powder is not freely flowing?

2.  Drum is mislabeled?

3.  Wrong powder in the drum?

 

4.  Drum hoist is not used?

5.  Two drums are added?

6.  Drum is misweighed?

7.  Drum hoist fails?

 

8.  Drum is corroded?

 

 

9.  Ventilation at Mix Tank is not operating?

10.Granular powder becomes dusty?

11.Powder gets on operator’s skin?

12.Tank liquid level too high?

1.  Back injury potential when breaking up clumps

2.  Quality issue only

3.  If wet, could cause exotherm

4.  Back injury potential

5.  Quality issue only

6.  Quality issue only

7.  Leg, foot, back, arm injury

8.  Iron contamination as well as drum failure & injury

9.  Dusting & potential operator exposure

10.Same as above

 

11.Possible burn

 

12.Possible caustic splash as well as quality issue

 

 

 

 

Figure C-3.  Example of Completed Step Nos. 1 & 2 What-If Analysis Form

 

            If done correctly, reviewing the potential equipment failures and human errors can point out the potentials for not only safety and health improvements but also the opportunity to minimize operating and quality problems.  Including the operators and trades personnel in the review can bring a practical reality to the conclusions that will be reached.

 

            3.            Assessing the Risk & Making Recommendations – Not having considered the answers to the “What-If” questions, the next task is to make judgments regarding the likelihood and severity of that situation.  In other words what is the risk.  The review team needs to make judgments regarding the level of risk and it’s acceptability.  For example, consider the following risk judgments and recommendations to the answers in our example as illustrated in Figure C-4.

 

 

Division:  Chemical Ops

Desc. of Operation:  Manufacturing B Mix/Drum Charging Operations – Page 2 of 4

By:  Review Team Date 9/97

 

 

What If?

Answer

Likeli-

hood

Conse-

quences

Recommendations

 

1.  Granular powder is not freely flowing?

2.  Drum is mislabeled?

3.  Wrong powder in the drum?

 

4.  Drum hoist is not used?

5.  Two drums are added?

6.  Drum is misweighed?

7.  Drum hoist fails?

8.  Drum is corroded?

 

 

 

9.  Ventilation at mixing tank is not operating?

10.Granular powder becomes dusty?

11.Powder gets on operator’s skin?

12.Tank liquid level too high?

1.  Back injury potential when breaking up clumps

2.  Quality issue only

3.  If wet, could cause exotherm

4.  Back injury potential

5.  Quality issue only

6.  Quality issue only

7.  Leg, foot, back, arm injury

8.  Iron contamination as well as drum failure & injury

9.  Dusting & potential operator exposure

10.Same as above

 

11.Possible burn

 

12.Possible caustic splash as well as quality issue

   Quite

Possible

Remote

Unlikely

 

Possible

Remote

Possible

Remote

Remote

 

Unlikely

 

Unlikely

 

   Quite

Possible

Remote

Serious

 

Serious

 Minor

 

Serious

 Minor

Serious

Serious

Serious

 

 Minor

 

 Minor

 

Serious

 

  Very

Serious

Design delumping equipment

 

Contact vendor

Include inspection in procedure

 

Train personnel & ensure use

None

Require 2nd check on weight

Ensure hoist on PM program

None

 

Include vent check in SOP

 

None beyond existing procedure

 

Use dust suit & gloves

 

Use goggles and apron

 

Figure C-4.  Example of Completed What-If Analysis Form

 

            Notice that the team has not only assessed the risk at each situation but has also made their recommendation at each situation.  The discussion of each situation leads naturally to the recommendation.  The team will then continue the review question by question until the entire process or operation has been analyzed.  At this point, the facilitator should have the team step back and review the “big picture” and determine they have inadvertently missed anything.

 

D.            Reporting the Results – To Whom & How?

 

            The hard work of conducting the analysis has been competed.  The important work of reporting the results still remains.  The make up of the organization generally determines to whom and how the results get reported.  Usually, the department or plant manager is the customer of the review.  The leader of the review team will generate a cover memo that details the scope of the review as well as the major findings and recommendations.  In some organizations, the report recommendations will also include who has been assigned the responsibility to follow up and time frame.  In other cases, a separate staff or function will review the recommendations and determine the actions required.  A periodic report is then generated to summarize the present status of each of the recommendations.  Those organizations that have a well developed hazard review program require follow-up assignments every three to five years based on the associated hazard levels.

 

E.            “What-If” Summary – Pros and Cons

 

            The What-If Analysis technique is simple to use and has been effectively applied to a variety of processes.  It can be useful with mechanical systems such as production machines, with simple task analysis such as assembly jobs, as well as with reviewing tasks in chemical processing.  No specialized tools or techniques are needed.  Individuals with little hazard analysis training can participate in a full and meaningful way.  It can be applied at any time of interest such as during construction, during debugging, during operations, or during maintenance.  The results of the analysis are immediately available and usually can be applied quickly.  This is especially true if the review team members also operate or maintain the system being assessed.

 

            On the other hand, the technique does rely heavily on the experience and intuition of the review team.  It is somewhat more subjective than other methods, such as Hazard and Operability Analysis (HAZOP), which require a more formal and systematized approach.  If all of the appropriate What-If questions are not asked, this technique can be incomplete and miss some hazard potentials.  It may be appropriate to assign those more dangerous portions of the system to a more rigorous review such as HAZOP.