Background on Threat and Vulnerability Analysis

In evaluating any protective measure, numerous factors need to be considered so that realistic outcomes are accurately determined. Key factors include:

- Threat or weapon
- Target
- Intent

Threat or Weapon
Credible threat must be considered. For normal security applications, we will evaluate (unless otherwise directed by the client) the effects of homemade explosives (HME) and improvised explosive devices (IED). These systems are typically low yield in terms of 2,4,6-trinitrotoluene (TNT) equivalence but is sufficient to produce high blast output capable of significant damage when deployed against ordinary commercial structures. The evaluation takes into account whether the IED is man-portable or vehicle mounted (on motor bike, car, delivery van or large truck) and whether the device is to function with stand-off from the target, in contact with or inside the building. Location as well as size and type of weapon are crucial in determining the severity of damage caused. In our modelling, we will take into account both the effects of blast and fragmentation from structural failure.

Materials of construction and building design are crucial aspects when considering response to shock loading from blast as well as fragment produced by failing structural components. Key considerations are the protection of personnel and the protection of business infrastructure. This includes whether protective measures are installed as retrofit or during construction phase. Overall security assessment must include not only mechanical aspects of existing or proposed architecture but also on-going security arrangements and installations.

The intents of credible threats include:
- Stop or interrupt business 
- Maximize injury to personnel (blast, fire, fragment attack)
- Cause significant structural damage to buildings
- Complete destruction of target

Although the terrorists may aim for complete structural destruction, this is usually extremely difficult to achieve with improvised weapon systems. However, significant damage can still be inflicted on building and people from both the primary (weapon borne) attack and secondary effects (such as fire or subsequent failure of electrical or water systems). 

Only through a complete appraisal of the building, protective and security measures can a realistic business threat assessment be provided. Without this information the value of considering or installing any protective measure is diminished.  By performing an in-depth and thorough analysis, which includes sophisticated computer modelling, Jimmy Lea Pty Ltd can advise on security measures which represent the best value for money outcome for given threat levels whilst maximising protective effect.

Scope of Work

Within infrastructure resilience, we have the capability to model and analyse the following items:
- Applicable to a wide range of terrorist events involving explosives
- Minor or major structural damage
- Potential for collapse
- Window fragmentation
- Determine the expected damage
- Vulnerability of stored ammunition store
- Missile attack, aircraft impact, car bomb
- Marine blasts and ship damage
- Street blasts, building blasts
- Provides insight into ways damage could be mitigated through design and protection
- Determine the protective performance of structures, buildings, vehicles and body armour
- Advanced materials – glass (including laminations PVB), ceramics, polymers

conquering unknowns

Apart from enhancing building resilience, CFD and END can also be employed in the area of Conquering Uncertainly.

CFD is the science of predicting fluid flow, heat transfer, mass transfer, chemical reactions and related phenomena by solving the governing mathematical equations. Using CFD, we can conquer uncertainty by predicting the outcome, assessing, designing and/or optimising the performance of: armoured vehicle, tanks, naval ship/submarine & submarine propeller cavitation (loss of stealth), fighter jets/UAV, projectiles, missiles/rockets/torpedoes, equipment that manufactures energetic products, behaviour of toxic gas release, gas masks and many ‘what if’ scenarios.

END simulation aims to simulate large material deformation or failure. It provides advanced solution methods to simulate many attacks scenarios such as the detonation of explosives followed by the propagation of shock waves and its impact on surrounding materials. Using END, we can conquer uncertainty by predicting the outcome, assessing, designing and/or optimising the performance of: aircraft impacts, blasts in buildings, body armour, crushing, drop tests, improvised explosive devices (IEDs), marine blasts, mine blasts, projectile/warhead impacts, street blasts, vulnerability of stored munitions, sympathetic detonations, warhead design (shaped charges) and many ‘what if’ scenarios.

By conquering the unknowns, the probability of a project's success is significantly enhanced.



​Almost every day the media reports terrorist attacks in different parts of the world at times with dire consequences. Since the attacks on the United States’ World Trade Center, terrorism has become a significant concern for many governments and agencies. A terrorist attack can no longer be viewed as something that will only happen to others and security against terrorist threat is now on every government’s agenda. The protection of buildings has become one of the most important components not only because they are the preferred targets of terrorist attacks, but also because they represent an organisation’s major assets and wealth. Hence, the formation of the Critical Infrastructure Centre on 23 January 2017, under the responsibility of the Attorney-General’s Department.

Buildings are constructed today in accordance with relevant building codes that lack substantial design considerations intended to prevent or mitigate the impact caused by explosive blast or chemical, biological and radiological (CBR) attacks. Building collapse or structural damages sustained can have severe impact on the building’s owner, all sectors of the economy, or even worse, result in significant loss of life. Hence, today’s building designs must integrate the traditional code and guidelines with safety and security measures along with other environmental and economic considerations. The protective function of such integrated building design aims to mitigate the risks from hazards and threats that may cause building damages, harm occupants or passers-by, impair critical function, and inflict economic and other losses. Integrated building design must therefore rely on the best available information about prevailing risks and the best protective measure that can be deployed against these risks. 

Through our Simulation Services, Jimmy Lea Pty Ltd identifies the principal components of risk, analyses their relative magnitude and provides guidance to building owners with respect to cost-benefit decision making to mitigate risks. Jimmy Lea Pty Ltd is a specialist engineering firm, founded in Sydney Australia in 2011 and headquartered in Sydney, with international representative offices in Singapore, Indonesia, Malaysia and Vietnam. Our standard approach includes using advanced engineering and in-depth analysis that goes beyond simply adopting rule-of-thumb guidelines. Whilst rule-of-thumb provides a starting point for most design works, it has the tendency to overdesign which eventually leads to higher overall costs. We aim to provide surgical accuracy design recommendations to ensure the system of interest meets the client’s objective whilst minimising the total implementation costs.​