RAM ANALYSIS- ENGINEERING PHASE

Do you know what is RAM analysis??

NO, I am Not Talking about Bhagavan Shri RAM-??????

R A M (Reliability, Availability, and Maintainability) analysis is a well-known method of estimating the production availability of a system by assessing failure modes, frequencies, and consequences. The intention is to find out if the estimated production availability meets the requirements and to identify the most cost-efficient parameters to help pave the way for an optimum solution in terms of profit.

• Reliability?– It is the ability to perform a specific function and may be given as design reliability or operational reliability. The fundamental parameter for determining the reliability of an object is its?failure rate, i.e. the number of failures it undergoes in the set time of one hour.
• Availability?– it is the ability to keep a functioning state in the given environment.?It is the probability that a device’s performance will be unchanged over time. Availability studies take into account the?maintenance?to be carried out on the system and the time needed to restore it;
• Maintainability?– the ability to be timely and easily maintained (including servicing, inspection and check, repair, and/or modification).

So when Should We?conduct?a?RAM Analysis??-??-??

RAM analysis can?be conducted at various stages of the life cycle of the project based on the availability of data. Pre-FEED, FEED, and Detail Engineering at any stage. But during every stage, the level of details and depth differs.

Pre-FEED (i.e. design conceptualization) –?RAM analysis can be used to compare various design options that are being considered through quantification of the production output of each option.

Conducting a RAM analysis at this stage, whilst the design is still being finalized is known to reduce the cost and schedule impact on the project than if conducted at a later stage.

FEED –?At the FEED stage, when critical equipment is being identified which could cause significant production losses. A RAM analysis would normally be conducted to optimize the equipment configuration and identify the requirements of any further spares or equipment redundancies in order to optimize the availability of the system.

Detailed Engineering –?At the detailed engineering stage it is likely that the design is frozen with minimal changes. A RAM study at this point would help in identifying performance targets that must be met by the equipment, which can be used as part of the equipment design specification during procurement.

Process Operation –?Whilst the process is in operation, conducting a RAM study using the data of the as-built facility can bring the benefit of identifying unreliable equipment which may be a leading cause of production losses.

Benefits of RAM Analysis:

The benefits of undertaking RAM Studies include:

• A reduction in the maintenance and sparing costs, while maintaining and/or increasing production levels;
• A decrease in the duration of any unplanned and planned outages;
• Optimization on capital investment by reducing the cost of production;
• Optimization of capital improvement options at the plant and enterprise levels when improve budgets are constrained;
• Accurate forecasts of equipment lifecycle costs that reflect the equipment age, duty cycle, and maintenance effectiveness;

Inputs required to conduct RAM analysis:

As a minimum the following information would be required in order to conduct the analysis:

• ?P&ID’s/PFD - showing Equipment configuration and sparing
• ?Equipment List - Detailing the dimensions, operating, and design parameters
• ?Description of Modes of Operation - Shutdown, start-up philosophy documents highlighting various different start-up and shutdown scenarios.
• ?Maintenance Philosophy - Usually an operations input obtained from the historic plant maintenance data.

Based on the project requirements, additional information may be required like production profiles, operations historical data etc.

RAM METHODOLOGY:

The figure below provides a beautiful overview of RAM methodology(Image courtesy-Petroleum SWPU).

For RAM analysis the first step always starts with the system components and examines the design to determine the effects of individual component failure, often using a Reliability Block Diagram (RBD).

Equipment failure data are then applied to each component in the system. These data can be obtained from several sources such as manufacturing data, design specifications or operational experience. The key to a successful and accurate study is the quality of the failure data. In cases where failure data specific to the actual component are not available, generic, industry-standard sources are normally used.

Then Using specialized RAM software, operational availability can be predicted and analyzed. The software may be industry-standard packages such as MAROS or any other similar ones.

Some of the more common pitfalls to avoid when conducting RAM modeling are

• Setting Unrealistic RAM targets
• Not using proper failure data
• Manipulating the model to justify the Top management decision
• Neglecting preventive maintenance programs
• Conducting RAM as just a textbook exercise without engaging with Engineers, operations, and maintenance team.

CONCLUSION:

Once the baseline RAM of the system is established, the following considerations should be addressed:

• Has the design met all the RAM requirements and targets?
• Can the design or operation be modified to increase the availability of the system?
• Can the maintenance strategy be revised to reduce downtime in the event of a failure?

RAM modeling has a long history in the engineering sector. Used appropriately, RAM modeling is an effective tool for assessing system reliability, availability and maintainability, and is crucial to support the through-life viability of a project