Thursday, March 13, 2008

Forensic Engineering Evaluation of Premises Maintenance

Forensic Engineering Evaluation of Premises Maintenance


A premises (building and its site) consists of components to form a safe, usable facility. The components must be maintained in order to keep them functioning. Forensic engineers are often asked to render their opinions concerning a component’s performance and the maintenance it has received. Because the results are to be used in a forensic forum, the engineer must have a well-documented methodology and a firm basis for his or her opinions. One method of making such an evaluation is to employ a systems approach.

When a component and its maintenance are treated as a system, the engineer considers its various aspects and the interaction between those aspects. Furthermore, the examiner can test “what if” hypotheses using the same method. This article discusses a method to achieve that end while giving the forensic engineer a strong foundation for his or her opinion.



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This article is approved by the following for continuing education credit:

(ACFEI) The American College of Forensic Examiners International provides this continuing education credit for Diplomates.

By John A. D’Onofrio, MS, CE, PE, DABFE, DABFET, DNAFE

Key Words: buildings, premises, maintenance, systems evaluation


A premises (buildings and its site) consists of a group of systems working together to form a facility. The components of these systems must be maintained in order to keep them functioning. Following an accident or system failure, a forensic engineer is often asked to make an examination and render an opinion concerning a component’s performance and the maintenance it received. Such requests are most common in civil litigation, but may be required in a criminal case as well. Because of the complexity of a premises (both the building and its site), such services may be requested from engineers in many disciplines and some examinations may require an interdisciplinary team. Because the result is to be used in a forensic forum, the engineer must have a well-documented methodology and a firm basis for his or her opinions.

One method to make such an evaluation is to employ a systems approach. System analysis, as defined in this article, is the critical examination of the technical and managerial skills used to maintain the premises. This approach recognizes that continued, acceptable operation of a component is dependent upon a system consisting of the component itself and the maintenance it receives. Systems, whether including human activity or not, are subject to limitations whose effects can best be understood through system analysis. Furthermore, the examiner can test “what if” hypotheses by assuming changes in the system and analyzing the results. The result of an analysis is a simple statement of opinion; however, time, work, and data are needed to posit an opinion with a strong foundation.

The remainder of this article discusses a method to achieve that end. Many of the principles discussed have their origin in health and safety engineering. Often, premises maintenance evaluations are required when an accident or injury has occurred. Therefore, the method described here is closely related to safety engineering practice.

The Flow Chart (Figure 1)

By applying the evaulation flow chart, the examiner covers a wide range of pertinent topics. Not only does this provide a guideline to the examination, but it also provides an excellent foundation for the engineer’s opinions. The flow chart has two flow paths, Component and Maintenance. Each path consists of decision points where the engineer finds the aspect under consideration either acceptable (yes) or unacceptable (no). A “no” evaluation leads to an Inadequate System rating. A series of “yes” evaluations leads to the And gate toward the bottom of the flow chart. Both paths of the flowchart must be evaluated and lead to the And gate in order for the system to receive a Good rating. If the first path leads to the And gate, then the second path must be evaluated to complete the process.

Once an Inadequate System rating is reached, theoretically, there is no need for further evaluation. However, an Inadequate System rating is often the beginning of the next phase of the investigation, an explanation of cause. Because a system may be inadequate for numerous causes, the engineer alone must decide whether he or she should continue the evaluation further.

An Example

The following example follows Figure 1 and includes a discussion of the evaluation process. The example is a request to evaluate the floor of a small mercantile establishment where a patron slipped and fell on a rainy day. There is an allegation that water was present on the floor at the time of this fall. The component to be evaluated is the flooring. The maintenance program is that which the proprietor uses for safety during inclement weather.

Operating Conditions

The first step in the evaluation process is to determine the operating conditions. These are the conditions under which the system is expected to operate and give the engineer insight to the system when working the evaluation paths.

The operating conditions are best determined by site inspection, document review, and testimony of various parties. A document review may include but is not limited to:

  • Plans and specifications prepared by the building architect or design engineer
  • Lease documents that may specify permitted activities within the building
  • Building and maintenance codes
  • Zoning ordinances and other regulatory documents
  • Indoor environmental standards common to the industry

In this example, the site inspection revealed that the space was being used as a haberdashery. Flooring was a commercial grade vinyl tile. The slip location was approximately 7 feet from the entry. The document review has determined that, at the time of the fall, the building was approximately 25 years old. The architect’s plans indicate the space to be used for retail use. The use of the space for mercantile purposes is consistent with the permitted uses in the zoning ordinance. The lease between the owner and tenant indicates that the space is to be used for the legal, retail sale of goods, not to include food or personal services. Based on the site inspection and document review the engineer can reasonably conclude that the use of the space is “anticipated.”

Note from Figure 1 that the evaluation process does not depend upon the operating conditions; however, if unanticipated conditions are involved, the examiner must decide and note if the evaluation is made for the actual conditions encountered, the anticipated conditions, or both. The examiner must also recognize that a component may be exposed to an unanticipated condition and continue to function well.


Component evaluation follows the right side of Figure 1. Here, the specific component under examination is scrutinized under the chosen operating conditions.

Component Specifications. The next step in component evaluation is to determine if it meets specification. This step implies that the engineer has determined the component’s specification and an appropriate test for compliance. The component specification may be either specific (specified by size, make, and model) or performance (i.e. 100 cfm fan, 230VA) oriented. Oftentimes, component specifications are not specific and must be derived from document review. These include, but are not limited to:

  • Plans and specifications prepared by the building architect or design engineer
  • Manufacturer’s specifications
  • Building codes
  • Typical architectural and engineering details (graphic standards)
  • Engineering organization standards
  • Authoritative consensus standards

In the example, the architectural plans were silent on the flooring material. According to testimony, the vinyl tile was selected by the owner and was in place when the tenant moved in. The manufacturer is unknown at this time. The tenant space was inspected by the construction official before opening to the public and received a certificate of occupancy. The local building code requires that all walking surfaces be slip-resistant.

A literature search revealed an ASTM standard that relates slip resistance to the floor’s static coefficient of friction with a shoe-leather test surface and a threshold level. On-site testing of the floor material was conducted and determined it to be slip-resistant.

Based on the site inspection, document review, and testing, the engineer can reasonably conclude that the material used to construct the floor surface meets specification.

Component Installation. The next step in Figure 1 is to examine the component installation. Poor workmanship should be noted and described. The manufacturer’s installation guide for the component should be consulted, if possible, whenever installation is drawn into question. In the example, the vinyl tile was examined and found to be tight, stable, and planar. Based on the site inspection, the engineer was able to reasonably conclude that the installation was not an issue and probably followed the manufacturer’s specification.


The maintenance flow path follows the left side of Figure 1. Here, the maintenance program under examination is scrutinized under the chosen operating conditions. This flow path incorporates work on safety done in the United States and the United Kingdom. The U.S. recommendations were developed and promulgated for workplace safety. The U.S. Department of Labor, through the Occupational Safety and Health Administration (OSHA), publishes a document entitled Keeping Your Workplace Safe (1999). This document describes four elements that every effective program should have:

  • Management, leadership, and employee involvement
  • Workplace analysis
  • Hazard prevention and control
  • Training and education

Similarly, the Health and Safety Executive of the United Kingdom publishes a document entitled Managing Health and Safety – Five Steps to Success (1998). The document states: “This leaflet contains notes on good practice which are not compulsory, but which you may find helpful in considering what you need to do.” The five steps are

  • set up your policy;
  • organize your staff;
  • plan and set standards;
  • measure your performance;
  • learn from experience.

Figure 1 incorporates these into the four aspects of the maintenance procedure flow path.

Maintenance Procedure

Maintenance procedures may be written and formalized. This is commonly found at locations that have a maintenance department or are part of a nationally operated or franchised establishment. Managers responsible for large buildings or multiple premises may have routine and preventative maintenance scheduled and noted by computer. On the other side of the spectrum, other business or industrial locations may not have a written plan, and the examiner must determine the maintenance procedure through investigation, interview, or testimony.

The second aspect of the maintenance procedure is to determine if it conforms to or follows a standard. The examiner must keep an open mind and not judge the book by its cover. Policies and procedures that are extensive, written, and neatly bound are not necessarily more compliant with standards than those that are less organized. A lack of organization and record-keeping may be a regulatory violation, but is insufficient by itself to consider the system inadequate. However, policies and procedures that are unclear may be considered outside the standards because of ambiguity. Further, loosely stated maintenance procedures can have an effect on other aspects of the maintenance program.

The engineer must determine the appropriate standard by which to measure the subject procedure. The manufacturer’s specification on how to maintain the component should be investigated and may specify a performance standard for maintenance. For example, certain filters may need to be checked at a maximum time interval and cleaned following a specified process. Property maintenance regulation may specify the maximum time that snow or ice may be allowed to remain untreated or the length of time that rainwater may accumulate before it is considered stagnant.

In cases where the standard is not straightforward, the engineer must be prepared to ascertain industry standards for maintenance based on authoritative and circulated industry publications. Standards organizations such as the American Society of Testing and Materials (ASTM) and the American National Standards Institute (ANSI) publish a wealth of information. The insurance industry has a long history of underwriting standards for buildings and sites. They pioneered sprinkler system standards for fire control, and many insurance companies sponsor safety research to this day. Over time, these findings become industry standards and find their way into loss-control and underwriting literature. The National Safety Council (NSC) and the American Society of Safety Engineers (ASEE) are another source of information. The U.S. Army Corps of Engineers and the Air Force have extensive procedures for maintaining buildings and sites with a wealth of information available on their websites (Secretary, 2004; U.S. Army, 2003).

When deciding on an appropriate standard, the examiner must be sure that the standard is widely circulated and does not conflict with jurisdictional building codes, maintenance regulations, or site improvement standards. The challenge is to determine reasonable industry standards for a given situation, especially in view of critics that are always present around any issue. Cutting-edge academic and scientific papers should be used with caution. They may be useful to explain or substantiate a principle, but most are not widely circulated amongst maintenance practitioners, and the author’s view may not be widely accepted or adopted as a standard.

When researching standards, remember that a maintenance procedure in practice must include a method of discovering conditions that need to be maintained. Discovery of a condition that has developed relative to a component is an essential part of maintenance. The time required to correct such conditions (correction time) includes both the amount of time the condition exists before it is discovered (discovery time) and the amount of time required to do the work using reasonable dispatch (work time). Hence, there will always be a time interval between the instant a component develops a condition requiring work and when the work is completed. Often a condition that develops will not be obvious and the maintenance procedure must be proactive to minimize the discovery time. For example, mechanical equipment should be checked on a periodic basis to assure it is either functioning properly or exhibiting telltale signs of impending failure.

Published standards must also be read with this principle in mind. They will often indicate that certain actions must be taken “immediately.” This should be interpreted as acting “without delay upon discovery” because instantaneous discovery (zero discovery time) and correction (zero work time) is, in most cases, impossible.

The procedure and standard examination may require some iteration. The examiner should have the standard in mind when examining the procedure and the procedure in mind when examining the standard. After interviewing the various parties or reviewing their deposition testimony, review both the procedure and the standard for modifications afterward. This will help assure that nothing out of the ordinary is missed.

In the example, the engineer researched Best’s Loss Control Manual (2000), a loss-control engineering guide and authoritative publication for insurance underwriting. After selecting the appropriate use, he reviewed the various items of concern and selected those that were appropriate to floor maintenance and the conditions at hand. This subset of conditions became the performance standard for the evaluation. Also, it was determined that local building and maintenance codes provided no performance standard for floor maintenance. Further review of a NSC publication concerning falls on floors revealed similar recommendations therein. The engineer felt confident that the items selected represented good practice and industry standard.

The maintenance procedures for floor maintenance were written and posted on the bulletin board in the employee area of the store along with emergency phone numbers. While not detailed, they covered the items in the standard and were straightforward and easy to understand. They included employee assignments and response measures to inclement weather conditions. The engineer determined that the maintenance procedure did follow standard.


Education refers to the training that maintenance personnel receive. Depending upon the maintenance tasks, the education may require specialized training or schooling. Most commonly, however, maintenance personnel receive on-the-job training, especially if the maintenance tasks are more janitorial than repair in nature. Management must be involved to assure that education is not a one-time experience. New equipment or changes in business operations may require re-training of maintenance personnel. Further, it must also be determined that the specific personnel responsible for the maintenance had received the training and understood their duty. Maintenance personnel must be taught and encouraged to trust their judgment and report their opinions concerning the component or the maintenance procedure to management without fear of reprisal.

In the example, it was determined that all employees are instructed as to the safety procedures for inclement weather. The maintenance was basically a janitorial function. Safety posters were on the employee bulletin board, and the owner discussed safety at all employee meetings, instructing them to place mats on the floors and warning cones at the entrance when it starts to rain. Employees were instructed how to properly clean water and spills from the floor and to watch for such conditions as they move about the store. The specific employee at the store when the incident occurred had 3 years of experience with the company and was thoroughly familiar with the procedures. The engineer concluded that the personnel were sufficiently trained to properly maintain the floor.


Management works hand-in-hand with education and is a critical component in resources. Management must consider maintenance a priority aspect of their business and be committed to keeping the system working. The attitude of management influences the personnel; if the boss does not care, neither will the staff. Management should

  • have a system of reporting and tracking maintenance functions. This data can point to problems and the need for improvement in the system;
  • check to assure that adequate resources in the form of manpower and equipment are available to keep the system running;
  • reinforce education amongst the workers;
  • create a climate where maintenance is a priority.

Sometimes an evaluation of management can be simple and straightforward. In other situations, it can be complex and difficult. A proprietor of a space that ships and receives merchandise from one or two loading docks may have no problem both scheduling and managing his truck traffic. The traffic manager for an industrial or warehouse operation may have traffic engineering and safety problems to be solved while, at the same time, keeping the system running. It is important that the examiner keep his own house in order and recognize when a consultant or team approach is required.

The proprietor of the establishment in the example had two locations to manage. He visited both of them more than five times a week and had constant cell-phone contact whenever the stores were open for business. He met with employees and conversed with each one every 2 weeks. Premises maintenance was always discussed. Furthermore, he rotated and replaced the signs, posters, and instructions posted in the employee areas. Based on this testimony, the engineer concluded that the management of the system is adequate.


Resources are the manpower, equipment, and material required to keep the maintenance program working. It is tied to management because management allocates the funds, hires the people, and sets the work schedules. Management also determines how and when the resources are allocated. Personnel view resources as a management statement, equating adequate allocation of resources to a top management priority. Conversely, management that is perceived as “doing-it-on-the-cheap” is considered to have maintenance as a low priority.

Although budgets are an important factor in any business, resources are best measured by what takes place at the premises. It is one thing to budget for an adequate number of filters and another thing to have them in the supply room when they are needed. It is one thing to budget for a snow removal contractor and another thing to have sufficient manpower to do the job properly. Therefore, resources are a topic of investigation with both management and the personnel at the site.

At many small premises, maintenance responsibilities are shared amongst the general staff. Workers in a machine shop may also do regular maintenance on the machines and pitch in for janitorial work. At large premises, there will be a maintenance department. Each can be satisfactory, and each presents challenges to the examiner. Staffing levels will vary from place to place, and the examiner will often rely on management testimony concerning overall staffing levels. However, the examiner needs to assure him or herself that there is adequate manpower to maintain the component under consideration. In any examination, testimony from the personnel specifically assigned to the component’s maintenance will be valuable. This is another area where the examiner may need input from a consultant.

Communication is another resource. At small premises, a few employees can respond quickly when a condition arises based on verbal communications. Larger premises may require radio or telephone communication systems to report a condition when it is discovered and to dispatch personnel to do the work.

The engineer must keep in mind that a maintenance evaluation of a particular building component is not an examination of the entire building. If the examiner fails to properly limit his investigation, he runs the risk of following many irrelevant paths at a cost of much time and effort. He also exposes himself to irrelevant information that clouds his judgment. This leaves the engineer open to charges of bias or “witch-hunting.”

In the example, the proprietor scheduled a minimum of two employees on each shift, one for general operations and one at the cash register. The retail space is not large and the operations employee were easily able to make half-hour inspection rounds. Furthermore, he observed the store while moving about and assisting customers and responded to instructions from the cash register station by a hand-held radio. Floor mats, warning signs, mops, and buckets were kept in the maintenance closet. Floor mats were serviced by an outside contractor every 2 months. Three mops and buckets were available—one for each employee and a spare.

Based on the site inspection and testimony from the various parties, the engineer concluded that the system was supported by sufficient resources to properly maintain the floor during wet weather. This results in a “yes” for resources.

However, during his examination the engineer discovered that one employee was sick the day of the incident, leaving only one person to man both the cash register station and cover general operations. There was no one else available to cover the shift. When the rain started he placed the mats and warning signs at the entrance. However, he was unable to make regular rounds of the store looking for water and spills on the floor. The water on the floor was brought to his attention when the patron fell.

Opinions and Conclusions

According to the flow chart, when there are two “yes” results at the And gate, the engineer can feel confident that the component is adequate and the maintenance system can keep it functioning properly under the expected operating conditions. Therefore, a Good System rating is in order.

The fact that a component has failed does not affect this rating; it is the system being evaluated and not a single event. Components and maintenance can fail, even in a good system, because all systems have limitations; they are subject to randomly occurring and unpredictable events.

In the floor accident example, the system recieved a Good rating. However, insight into the event under consideration was gained by analyzing the conditions at the time of the failure. A re-analysis using the staffing conditions on the day of the component failure resulted in a “no” (not adequate) classification for resources because staffing fell below management’s recommended levels, and proper inspections were not taking place because of the short-staffing condition. Under these conditions, the flow chart leads to an Inadequate System rating for that particular circumstance. The forensic engineer must clearly make the distinction between the system’s rating overall and its rating as operating at a particular time. This distinction can be important in a forensic forum.

The use of systems analysis, as presented here, offers the forensic engineer a methodology of evaluation that is both comprehensive and flexible. The example presented shows that the method has application to simple as well as complex systems. The engineer must remember that the analysis is only as good as the input data, the end result is the opinion of an engineer who may have to defend it, and this analysis and opinion are seldom the end of the questions to be answered.


A. M. Best Company, Inc. (2000). Best’s loss control manual (version 2006). Oldwick, NJ: Author.

Brauer, R. L. (1990). Safety and health for engineers. New York: VanNostrand Reinhold.

Health and Safety Executive Books. (1998). Managing health and safety—Five steps to success. United Kingdom: Author.

Secretary of the Air Force. (2004). Safety and health standards. Washington DC: U.S. Government Printing Office.

U.S. Army Corps of Engineers. (2003). Safety and health requirements manual. Washington DC: U.S. Government Printing Office.

U.S. Department of Labor. (1999). Keeping your workplace safe. Washington, DC: U.S. Government Printing Office.

Wausau Insurance Company. (1990). Hazard survey guide. Wausea, MN: Author.

About the Author

John A. D’Onofrio, MS, CE, PE, is a professional engineer in private practice with more than 30 years experience in the engineering design and forensic evaluation of buildings and premises. He holds a bachelor’s degree and a master’s degree in civil engineering from the New Jersey Institute of Technology. D’Onofrio is a licensed professional engineer in New York, New Jersey, and the Commonwealth of Pennsylvania and has been recognized as an expert in federal court and in the courts of all three states. He has taught at Rutgers University in New Brunswick, New Jersey, and at the Community College of Morris in Randolph, New Jersey. He has been a guest lecturer before the New Jersey Municipal Engineer’s Foundation and the New Jersey Society of Professional Land Surveyors.

This article published by Dr. O’Block

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