Using Decision Analysis Maps for Planning and Managing Spares in the Aviation Industry

Pierre Kacha

The US Coast Guard maintains a fleet of about 220 aircraft of four different types. These aircraft, including helicopters and fixed wing airplanes, are deployed to 26 air stations around the country and must be ready to take off at a moment's notice. Keeping the right number of spare parts in the right location within a tight budget is a complex and dynamic problem.

To keep the system in balance, spare parts must be purchased or repaired well in advance of the expected demand for parts dictated by mission tempo and fleet conditions. Some of these spare parts, manufactured overseas, require a two-year ordering and production lead time. At the same time, the fleet, often exposed to corroding sea water, is aging and requiring maintenance in new areas.

Item planners at the US Coast Guard's Aircraft Repair and Supply Center in Elizabeth City, NC are responsible for maintaining spare part supply chain balance. They have to make monthly and daily management decisions that will maximize aircraft fleet availability and stay within budget.

A critical set of decisions to item planners is to determine whether to buy new or to repair certain parts, and when to take such actions given possible demand, budget constraints and administrative and production lead time.

To make good decisions consistently, items planners require (i) total pipeline visibility and (ii) the ability to determine what set of actions will yield the best results. To accomplish these tasks with thousands and thousands of parts requires decision support tools than can address all key supply chain management processes, including planning and procuring repairs and new buys, managing the repair cycle and the return of defective spares, fulfilling demand by the stations, and managing budgets.

A Unique Approach

Decisions, such as the ones taken by spares item managers on a daily basis, are the heart of any business. Improving organizational decision-making is one of the most critical and productive way to improve business. decision/analysis partners uses a unique methodology to help identify decision support needs and to create effective programs to improve decisions in organizations.

The heart of this methodology is a decision map which captures the decision-making process in the form of a network of nodes and links, where a node represents a decision, and a link between two nodes represents the inter-dependency between two decisions. The value of decisions is represented by the weight of the outbound link. An interconnected network of decision nodes is called a decision path.

The value of a decision is measured by its 'doability' – a measure that includes qualitative criteria, such as the 'ease' of making the decision, and measurable criteria, such as the availability of supporting transactional or historic data, and its payoff – a measure of the 'return on decision' reflecting the decision's impact on achieving stated business goals. Payoff is estimated in terms of qualitative (e.g., customer satisfaction) and quantitative criteria (e.g., inventory reduction).

Decision analysis maps are different from process flows in that a decision may spawn downstream decisions of varied value. As a result, decision paths of lesser value can be ignored (or relegated), unlike process flows that require that all paths be 'traveled'. 

Decision analysis mapping is part of an overall series of steps as depicted below:

Following initial decision mapping, a series of tasks are designed to identify decision values, comparing current decision making to best practices, identifying gaps and developing a strategy to best address the decision making gaps.

The benefits of decision analysis maps are threefold:

• They enable the study team and management to visualize the business in a new and critical way, bringing insights into how the business works and highlighting key responsibilities. 
• Revenue and cost can be traced directly to actions, and actions can be directly traced to the absence of decision support tools or skills for instance.
• This methodology enables to prioritize investments by identifying the most critical decisions to be improved in terms of benefits to the business.

The figure below illustrates a decision map.

Applying Decision Mapping to Spares Management

The decision mapping exercise enabled U.S. Coast Guard commanders to develop a new, comprehensive view of their business, and to synthesize this decision view into four key decision questions specific to their business:

• How is the choice between repairing spares or buying new parts made?
• How are spares allowance levels determined at each location?
• How could trading partner relationships influence the balance of the supply chain?
• What should be considered to produce a balanced operating budget for the supply of spares?

Each of these decision areas encompasses a number of decision points for which a value analysis was conducted to (i) rank critical decisions and (ii) cluster them according to best business practices. The resulting decision clusters represent a normative decision map that supports spares management, and articulates key elements of the organization's decision-making strategy.

Once the strategy had been outlined, a gap analysis identified detailed skill requirements, the hygiene and completeness of the information capital, and the current complement of decision support tools. This gap analysis led to the development of a set of functional and organizational requirements.

Conclusion

Decision making is the most overlooked and least understood area of management, yet one of the most critical. Most management does not realize the extent to which routinely-made operational and planning decisions, made hourly or daily, shape business performance.

Decision analysis mapping is a methodology developed by decision/analysis partners that focuses on this important area. Decision maps highlight with clarity and simplicity the relationship between key decisions, how they are supported and what impact they have on the organization. Decision maps can unify the voice of the organization, and can serve as a focal point to champion and generate grassroots support for change initiatives. Finally, they are a powerful management tool to set strategic directions, develop tactical plans, and track progress against goals.

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