Beyond authorized versus assigned: aircraft maintenance personnel capacity.

Selected Reading

Introduction

Most would agree that aircraft maintenance has been and continues to be a challenging, complex task involving a delicate balance of resources to include personnel, equipment, and facilities. This balancing act occurs in a very hectic environment. The Air Force flies 430 sorties per day in support of Operation Iraqi Freedom and Enduring Freedom. A mobility aircraft takes off somewhere in world approximately every 90 seconds. (1) As the demand for aircraft continues to grow, the number of airmen who support these aircraft is declining. "Since 2001 the active duty Air Force has reduced its end-strength by almost 6 percent but our deployments have increased by at least 30 percent, primarily in support of the Global War on Terror." (2) This reduction in personnel is part of the Air Force's process of drawing down the total force by approximately 40,000 people, with many of these cuts in aircraft maintenance career fields. Also adding to the growing maintenance workload is an aircraft fleet which now averages almost 24 years old, with the average age still increasing. (3)

When it comes to aircraft maintenance, the Air Force depends on metrics to know whether or not we are measuring up to standards. Several metrics exist which attempt to measure the success or failure of our maintainers' efforts. One of the most recognized metrics is the total not mission capable maintenance (TNMCM) rate. Air Force Instruction 21-101 describes TNMCM as "perhaps the most common and useful metric for determining if maintenance is being performed quickly and accurately." (4) Although a lagging type indicator, it is one of several key metrics followed closely at multiple levels of the Air Force. Over the last several years, the TNMCM rate for many aircraft gradually increased. This fact was highlighted during a 2006 quarterly Chief of Staff of the Air Force Health of the Fleet review. Follow-on discussions ultimately resulted in the Air Force Materiel Command Director of Logistics (AFMC/A4) requesting the Air Force Logistics Management Agency (AFLMA) to conduct an analysis of TNMCM performance with the C-5 Galaxy aircraft as the focus. AFLMA conducted two studies in support of this request.

Background

The C-5 TNMCM Study II (AFLMA project number LM200625500) included five objectives. One of those objectives was to determine root causes of increasing TNMCM rates for the C-5 fleet. An extensive, repeatable methodology was developed and utilized to scope an original list of 184 factors down to two potential root causes to analyze in-depth for that particular study. These two factors were aligning maintenance capacity with demand, and the logistics departure reliability versus TNMCM paradigm. To address the root cause factor of aligning maintenance capacity with demand, a method of determining available maintenance capacity was needed. To meet this objective, a new factor designated as net effective personnel (NEP) was developed. NEP articulates available maintenance capacity in a more detailed manner that goes beyond the traditional authorized versus assigned personnel viewpoint. The remainder of this article describes the need for NEP and how the NEP calculations were developed during the C-5 TNMCM Study II. The NEP calculations were ultimately used in conjunction with historical demand to propose base-level maintenance capacity realignments resulting in projected improvements in the C-5 TNMCM rate.

[ILLUSTRATION OMITTED]

Personnel as a Constraint

The analytical methodology applied to the C-5 maintenance system determined that personnel availability was an important factor to consider. This idea is not new; indeed, the force-shaping measures underway in the Air Force have brought the reality of constrained personnel resources to the forefront of every airman's mind. Without exception, maintenance group leadership (MXG) at each base visited during the C-5 TNMCM Study II considered personnel to be one of the leading constraints in reducing not mission capable maintenance hours. The study team heard the phrase "we need more people" from nearly every shop visited:

"The biggest problem for the maintainers here is a shortage of people." (5)

"With more people we could get a higher MC [mission capable]. We're currently just scrambling to meet the flying schedule." (6)

"Hard-broke tails" and tails in ISO [isochronal inspection] get less priority than the flyers. We run out of people--we physically run out." (7)

The Air Force defines total maintenance requirements (authorizations) on the basis of the Logistics Composite Model (LCOM) and current manpower standards. LCOM is a stochastic, discrete-event simulation which relies on probabilities and random number generators to model scenarios in a maintenance unit and estimate optimal manpower levels through an iterative process. The LCOM was created in the late 1960s through a joint effort of RAND and the Air Force Logistics Command. Though intended to examine the interaction of multiple logistics resource factors, LCOM's most important use became establishing maintenance manpower requirements. LCOM's utility lies in defining appropriate production levels, but it does not differentiate experience. (8) Once these requirements are defined, the manpower community divides these requirements among the various skill levels as part of the programming process. Overall, the manpower office is charged with determining the number of slots, or spaces, for each skill level needed to meet the units' tasks. The personnel side then finds the right faces, or people, to fill the spaces.

One measure historically used to quantify personnel availability is the ratio between authorized and assigned personnel. While this ratio is an indicator of maintenance capacity, it provides only a limited amount of information. Authorized versus assigned ratios do not take into account the abilities and skill levels of the maintenance personnel, nor does it factor in the availability of the personnel on a day-to-day basis. These issues were addressed in the C-5 TNMCM Study II by quantifying "we need more people" beyond the traditional metric of authorized versus assigned personnel. This capacity quantification was done as part of the larger effort of aligning capacity with demand. The process of capacity planning generally follows three steps:

* Determine available capacity over a given time period

* Determine the required capacity to support the workload (demand) over the same time period

* Align the capacity with the demand (9)

The following describes how the study team pursued step 1, determining available capacity over a given time period, using data from the 436 MXG at Dover Air Force Base (AFB) and characterizing the results in terms of what the study team denoted as NEP.

Determining Available Capacity

When personnel availability and capacity are discussed at the organizational level, typically the phrase authorized versus assigned personnel is used. However, are all people assigned to maintenance organizations--namely, an aircraft maintenance squadron (AMXS) or a maintenance squadron (MXS)--viable resources in the repair process? Most maintainers will answer no. While it is true that all assigned personnel serve a defined and important purpose, not everyone in these organizations is a totally viable resource to be applied against maintenance demand. This impacts maintenance repair time and aircraft availability.

TNMCM time begins and ends when a production superintendent advises the maintenance operations center to change the status of an aircraft. The length of that time interval is determined by several things. One factor is the speed of technicians executing the repair, which includes diagnosis, corrective action, and testing (illustrated in Figure 1) the repair node of Hecht's restore-to-service process model.

As illustrated by the Hecht process model, there are other important components required to return an aircraft to service, but the pool of manpower resources required to support the repair node is critically linked to TNMCM time. Within a mobility aircraft maintenance organization, this pool represents hands-on 2AXXX technicians whose primary duty is performing aircraft maintenance. Specifically, the study team defined the technician resource pool as follows:

   Technicians: the collective pool of airmen having a 2AXXX AFSC,
   that are 3-level or 5-level maintainers, or nonmanager 7-level
   maintainers whose primary duty is the hands-on maintenance of
   aircraft and aircraft components.

The distinction of nonmanager 7-levels generally reflects 7-levels in the grades of E-5 and E-6. In active duty units, 7-levels in the grade of E-7 do not typically perform hands-on aircraft maintenance, but are instead directors of resources and processes--they are managers. (11) This is in stark contrast to Air National Guard units, where 2AXXX personnel in the senior noncommissioned officer ranks routinely perform wrench-turning, hands-on maintenance. (12) For the research detailed in the C-5 TNMCM Study II, personnel analysis centered on data from the 436 MXG at Dover AFB and utilized the study team's definition of technicians.

Net Effective Personnel

Authorized versus assigned personnel figures usually quantify the entire unit. With the definition of technicians in mind, it is important to consider three additional factors that introduce variability into the personnel resource pool. These factors are:

* Skill-level productivity

* Ancillary and computer-based training (CBT)

* Availability

[FIGURE 1 OMITTED]

The study team examined the influence of these three factors, as well as their impact on the viable resource pool for the 436 MXG. This collective impact yielded a new resource pool representing a depiction of effective capacity rather than just the authorized versus assigned ratio. Again, this new resource pool is denoted as Net Effective Personnel, or NEP.

Factor 1: Skill-Level Productivity

In order to accurately examine the quantitative adequacy of a resource, as well as how a resource has historically been used to meet demand, there must be parity among individual resource units. Consider the previous definition of technicians. If one were to select two people at random, would they be equally capable resources? Not necessarily, if one was a 3-level trainee and the other was a 5 or 7-level resource. In order to collectively examine people in terms of comparable resources, and to account for the skill-level variability in typical aircraft maintenance organizations, productivity factors were applied to the resource pool.

As part of this research effort, the study team utilized its strategic partnership with RAND Project Air Force. Through personal interviews with RAND personnel and review of recently published RAND research, the study team learned that RAND had explored the productivity of trainees and trainers in aircraft maintenance units. Trainees were defined as 3-levels, who are not as productive as 5- and 7-levels. Additionally, some 5- and 7-levels were not as productive as others because they spend time training and instructing 3-level personnel. (13) In terms of specific productivity based on RAND research, 3-levels were estimated to be 40 percent productive, 5-level trainers and nonmanager 7-level trainers were estimated to be 85 percent productive, and 5levels and nonmanager 7-levels were 100 percent productive if they were unencumbered with training responsibilities. (14) For the purpose of this analysis, the number of trainers was considered to be equal to the number of 3-levels assigned--a one-to-one ratio. The productivity factors for the viable resource pool are summarized in Table 1.

These productivity factors also are similar to results from additional RAND research at Travis AFB published in 2002. (16) Considering the productivity factors from Table 1, the net effect of these productivity factors alone was a reduction of the 436 AMXS viable resource pool by an average of 5.68 percent. (17)

Factor 2: Ancillary Training and Computer-Based Training

In recent times the impact of ancillary training and CBT has been such an important issue for Air Force senior leaders, that it was the sole topic of the airman's Roll Call of 9 February 2007. (18) This document indicated that some active duty airmen spend disproportionate amounts of time on ancillary training, which detracts from their ability to perform official duties. Moreover, the document suggested that some ancillary training may no longer be relevant. (19) In the context of the viable pool of aircraft maintenance technicians, this would mean that, some of the time, personnel resources may be on duty but unavailable to perform hands-on maintenance due to an ancillary training requirement.

A consensus majority of personnel interviewed during the study team's site visits echoed these concerns, describing an insidious growth of new training requirements in recent years. (20) An additional concern voiced by interviewees pertained to computer resources. Interviewees described a situation where office workers have ready access to a personal computer (PC), but dozens of maintenance technicians often share only a handful of communal PCs. Consequently, their ability to complete computer-based ancillary training is constrained. One unit training manager explained that in the past, a group training briefing would be conducted for an entire work center, fulfilling each individual's training requirement simultaneously. (21) Today, an online course issues the required certificate of completion for only one individual, thereby necessitating that each airman conduct the training individually. The net result is more time away from primary duties (for example, repairing aircraft). In order to assess the influence of ancillary training and CBT on the technician resource pool, the study team quantified the average daily impact.

A list of various ancillary and computer-based training items that are applicable to the relevant pool of aircraft maintenance personnel was collected from three data sources:

* The USAF Education and Training Course Announcement (ETCA) Web site (22)

* The unit training monitor at the AFLMA

* The unit training monitor for the 105 MXG at Stewart Air National Guard Base (ANGB)

The training was categorized by data source, course number (if applicable), and course name. Training was also categorized as follows.

* Mandatory for all personnel, such as law of armed conflict training

* Voluntary or job-specific, such as hazardous material management training

Also, requirements were identified by the recurrence frequency (one-time, annual, or semiannual). Some requirements are aligned with the 15-month aerospace expeditionary force cycle; this would equate to a yearly recurrence frequency of 0.8 (12/15). Finally, training was categorized by the duration in hours for each requirement as identified by the data sources.

Most training courses only take up a portion of the duty day. The average duration for courses considered was 2.8 hours, with many listed at one hour or less. In situations like these, a manager would still view the individual as available for the duty day. (23) Therefore, the study team examined the impact of CBT and ancillary training as a separate factor and not as a part of the availability factor (factor 3). Final calculations resulted in the following totals:

* Hours of mandatory one-time training (denoted [M.sub.o]), 101.5 hours

* Hours of mandatory annually-recurring training ([M.sub.a]), 67.2 hours

* Voluntary or job-specific one-time training ([VJS.sub.o]), 85.8 hours

* Voluntary or job-specific annually-recurring training ([VJS.sub.a]), 10.3 hours

In order to quantify the daily impact of these training items, the study team made the following assumptions:

* An 8-hour workday

* 220 workdays in a calendar year. (5 days per week x 52 weeks per year) = 260; 260--(30 days annual leave)--(10 federal holidays (24)) = 220 workdays

* 3-levels required all of the mandatory, one-time training

* 5-levels and 7-levels required only the annually-recurring portion of the mandatory training

* As an average, all 3-levels required 10 percent of the voluntary or job-specific, one-time training

* As an average, all 5-levels and 7-levels required 10 percent of the voluntary or job-specific, one-time, annually-recurring training

* As an average, all training durations would be increased 20 percent to account for travel, setup, and preparation (25)

When employing the above assumptions, the figures in Table 2 were calculated to be best estimates of the time impact of ancillary training and CBT.

The best estimates for CBT and ancillary training requirements account for 7.51 percent and 5.24 percent of the workday for 3-, 5-, and 7-levels, respectively. The complementary effectiveness rates for this factor are expressed as 0.9249 (1 - 0.0751) for 3-levels and 0.9476 (1 - 0.0524) for 5 and 7-levels. These rates are listed as the ancillary and CBT factors for 3-, 7-, and 5-levels respectively in Table 6.

Table 3 illustrates how these rates change when the percentages of voluntary and job-specific training (V/JST) or the percentage of travel and setup buffer are varied. The matrices in Table 3 illustrate the results of sensitivity analysis of various CBT and ancillary training factors that would result for combinations of voluntary or job-specific training, or travel and setup buffer ranging from zero to 25 percent. The range of all calculated factors is approximately 3 percent for both technician categories. Note that the CBT and ancillary training factors chosen utilizing the study team's assumptions are boxed and shaded. For both 3-, 5-, and 7-1evels, the calculated training factors fall very near the mean developed in the sensitivity analysis. Some values shown in Table 3 are the result of rounding. For the 436 MXG at Dover AFB, the net effect of these CBT and ancillary training factors alone was a reduction of the viable resource pool by an average of 1.58 percent. (26)

Factor 3: Availability

Manpower resources must be present to be viable, and on any given day, aircraft maintenance organizations lose manpower resources due to nonavailability. Examples include temporary duty (TDY) assignments, sick days, and other details. To illustrate, Figure 2 depicts the actual availability of 436 AMXS airframe and powerplant general (APG) technicians on day shift for Thursday, April 12, 2007. For this work center, on this particular day and shift, roughly 65 percent of assigned technicians were not available for the various reasons listed.

Much like aircraft maintenance, some events that take people away from the available pool are scheduled and known well in advance, while others are unexpected, such as illnesses and family emergencies.

Although scheduled and unscheduled events both have an impact, scheduled events are anticipated and can be planned for. Adjustments can be made and resources can be shifted. Consequently, resource managers want to monitor and manage scheduled personnel nonavailability to the greatest extent possible. In order to assess the impact of this factor on the resource pool, the study team monitored the personnel availability of the 436 AMXS at Dover AFB from 1 March through 30 April 2007 via 9 weekly snapshots. 436 AMXS supervision tracks manpower via a spreadsheet tool that identifies the availability status of each assigned 3-level, 5-level, and nonmanager 7-level in their hands-on maintenance resource pool. For AMXS, this represents technicians from six different shops, identified with the corresponding Air Force specialty codes (AFSC) as follows:

* Airframe and Powerplant General (APG)--2A5X 1 C, 2A5X 1J

* Communication and Navigation (C/N)--2A5X3A

* Electro/Environmental Systems (ELEN)--2A6X6

* Guidance and Control (G/C) (28)--2A5X3B

* Hydraulics (HYD)--2A6X5

* Engines (JETS)--2A6X1C, 2A6X1A

The AMXS snapshot spreadsheet is updated (but overwritten) continually as status changes occur. (29) By monitoring changes in these snapshots, the study team was able to examine not only the impact of personnel nonavailability in aggregate, but also the degree to which the discovery and documentation of events altered the size of the capacity pool. Using the Dover AMXS snapshots, the study team calculated the number of available technicians in the aircraft maintenance resource pool.

The study team monitored the actual availability figures for the 436 AMXS over the 9-week period of March and April 2007, for a total of n = 61 daily observations. Across all shifts, the total number of personnel assigned to the AMXS personnel resource pool was 411 for the month of March, and 412 for the month of April. Actual availability figures, however, were much lower. Table 4 summarizes the descriptive statistics of this analysis.

The upper row of Table 4 statistics reflects the actual number of technicians available, while the bottom row reflects that number as a percentage relative to the total number of technicians assigned. For example, in the month of March, the maximum number of available technicians observed was 202, or 49 percent (202 of 411) of the total assigned. The mean availability for March was 36 percent. These figures take into consideration that some of the nonavailable personnel may be performing duties elsewhere for the Air Force such as flying crew chief missions or other TDY assignments. Therefore, they would not be viable assets for the aircraft maintenance resource pool at Dover AFB. The net effect of this nonavailability factor was a reduction of the AMXS home station viable resource pool by an average of 65.39 percent. This is reflected as the 35 percent mean highlighted for March-April 2007.

As discussed previously with Factors 1 and 2, the productivity of available technicians is reduced due to skill-level training needs, as well as ancillary and CBT training requirements. The study team applied productivity factors from Table 1 and CBT and ancillary training factors from Table 2 to the observed number of available technicians in AMXS. These calculations quantified the final pool of viable personnel resources, which is denoted as NEP. Because of daily variations in the number of 3-, 5-, and 7-skill level technicians available, the factors were applied to each daily observation. In performing these calculations, the study team developed a representation of the effective personnel resource pool. Specifically, the NEP figures account for the realities of availability and productivity, and allow the resource pool to be viewed objectively, unconstrained by concerns such as skill-level differences. The value of such a resource picture is that it provides a suitable mechanism for comparing maintenance capacity (NEP resource pool) with maintenance demand. The summary descriptive statistics for the 436 AMXS NEP are indicated in Table 5. Averaging across the observed timeframe, the 436 AMXS had approximately 113 net effective technicians in its viable resource pool on any given day. This figure is approximately 27 percent of the total assigned quantity of technicians, again using the previously discussed definition for technicians.

Therefore, to arrive at the results shown in Table 5, the study team considered the factors from Table 1 and 2, as well as the ancillary and CBT factors complimentary effectiveness rates calculated.

Each factor and rate detailed to this point was assigned a new designation for ease of use in the proposed NEP equation. The newly designated factors, factor descriptions, and the associated values are listed in Table 6.

The T factors relate to training, the A factors relate to available personnel, and the P factors relate to productivity. These factors were applied to the number of available technicians as recorded in the AMXS availability snapshots using the newly proposed NEP calculation, shown as Equation 1. Equation 1 is the cumulative NEP equation which accounts for all three factors which create variability in the resource pool and yields a numerical quantity of net effective personnel. To determine the NEP percentage, one need simply divide the right side of the equation by the number of assigned technicians (7-level nonmanagers, 5-levels, and 3-levels).

Figure 3 provides an Excel spreadsheet snapshot of an example NEP calculation for a generic maintenance unit. The maintenance unit's NEP is calculated using Equation 1 by entering the personnel totals in each of the five categories in the left column. These values are then multiplied by the factors in the right column to determine NEP. In this example, the unit has 104 technicians available but the NEP is only 77. In other words, the practical available maintenance capacity is only 77 technicians, not 104 as it initially appears.

NEP = [T.sub.75] ([A.sub.75NT] + ([P.sub.t][A.sub.75T])) + [T.sub.3] ([P.sub.e][A.sub.3])

Equation 1. Net Effective Personnel

[FIGURE 3 OMITTED]

To summarize, the study team's arrival at NEP followed an iterative sequence of three factor reductions:

* Skill-level productivity differences, to include those for trainees and trainers

* Ancillary training and CBT

* The nonavailability of personnel

Figure 4 graphically illustrates these iterations based on the relative size of the impact of the three factors on reductions to the overall resource pool. As shown in Figure 4, nonavailability had the biggest impact, productivity factors were next, and finally the effect of CBT and ancillary training had the smallest impact.

In addition to AMXS, an Air Force Maintenance Group usually includes a separate equipment maintenance squadron (EMS) and component maintenance squadron (CMS). However, if total authorizations are under 700, EMS and CMS will be combined into a maintenance squadron such as the MXS at Dover AFB. Various flights within a typical MXS maintain aerospace ground equipment, munitions, off-equipment aircraft and support equipment components; perform on-equipment maintenance of aircraft and fabrication of parts; and provide repair and calibration of test, measurement, and diagnostic equipment. (30) Technicians assigned to MXS usually perform maintenance not explicitly linked to the launch and recovery of aircraft (as is the focus of AMXS). However, some MXS personnel directly support flight line activities.

A more complete representation of the net effective personnel pool for aircraft maintenance resources in an MXG would include not only personnel in AMXS, but also those in MXS. The number of nonmanager 7-levels, 5-levels, and 3-levels assigned to the 436 MXS was determined from Air Force Personnel Center data to be 318. (31) Using the study team's definition of technician, this results in 729 technicians in the 436 MXG (411 in AMXS plus 318 in MXS). However, because the study team could not obtain exact daily availability figures for MXS similar to those of AMXS, the study team applied each of the calculated daily NEP percentages for AMXS against the number of assigned technicians to MXS. This calculation yielded daily estimates of the number of NEP for MXS. Since AMXS and MXS are both aircraft maintenance units with many of the same AFSCs and similar demands on their personnel, any differences from actual numbers as a result of this method were considered negligible for this analysis.

[FIGURE 4 OMITTED]

The study team then added the AMXS NEP figures to the MXS NEP figures, resulting in a collective NEP figure for the flight line maintainers at Dover AFB. These collective NEP figures are shown in Table 7. The upper portion of the table shows the NEP figures grouped by columns (day of the week) with each row representing 1 of the 9 weeks over the entire period that data was tracked. The bottom section of Table 7 also displays the descriptive statistics for NEP across both AMXS and MXS combined. The highest average NEP value was 222 on Thursdays, representing approximately 30 percent of the baseline total of 729 people.

Conclusion

The ratio between authorized and assigned personnel is typically used to quantify personnel availability. While this ratio is an indicator of maintenance capacity, it provides only a limited amount of information. These ratios do not take into account the abilities and skill levels of the maintenance personnel, nor does it factor in the availability of the personnel on a day-to-day basis. The Net Effective Personnel methodology described in this article is a repeatable process which produces NEP figures that provide leadership with a better representation of the personnel resources and actual capacity available to an Air Force aircraft maintenance organization on a day-to-day basis. The NEP methodology will be tested further and validated using personnel data from other units to verify similar results and potential gains. Ultimately, the NEP methodology has the potential to be used alone or in conjunction with LCOM to better portray maintenance personnel requirements and capabilities based on experience and skill levels.

As previously mentioned, the NEP methodology described in this article was developed as part of the larger C-5 TNMCM Study II. The entire study can be found at the Defense Technical Information Center Private Scientific and Technical Information Network Web site at https://dtic-stinet.dtic.mil/.

Article Highlights

Ultimately, the NEP methodology has the potential to be used alone or in conjunction with the Logistics Composite Model to better portray maintenance personnel requirements and capabilities based on experience and skill levels.

"Beyond Authorized Versus Assigned: Aircraft Maintenance Personnel Capacity" quantifies the phrase "we need more people" beyond the traditional metric of authorized versus assigned personnel. The article is based on work done for a recent Air Force Logistics Management Agency project--C-5 TNMCM Study II. During this project, an extensive, repeatable methodology was developed and utilized to scope an original list of 184 factors down to two potential root causes. These two factors were aligning maintenance capacity with demand, and the logistics departure reliability versus TNMCM paradigm. To address the root cause factor of aligning maintenance capacity with demand, a method of determining available maintenance capacity was needed. To meet this need, a new factor designated as net effective personnel (NEP) was developed. NEP articulates available maintenance capacity in a more detailed manner that goes beyond the traditional authorized versus assigned viewpoint. The article describes how the NEP calculations were developed during the C-5 TNMCM Study II. The NEP calculations were ultimately used in conjunction with historical demand to propose base-level maintenance capacity realignments resulting in projected improvements in the C-5 TNMCM rate.

The ratio between authorized and assigned personnel is typically used to quantify personnel availability. While this ratio is an indicator of maintenance capacity, it provides only a limited amount of information. These ratios do not take into account the abilities and skill levels of the maintenance personnel, nor does it factor in the availability of the personnel on a day-to-day basis. The NEP methodology described in the article is a repeatable process which produces data that provides leadership with a better representation of the personnel resources and actual capacity available to an Air Force aircraft maintenance organization on a day-to-day basis. The NEP methodology will be tested further and validated using personnel data from other units to verify similar results and potential gains. Ultimately, the NEP methodology has the potential to be used alone or in conjunction with the Logistics Composite Model to better portray maintenance personnel requirements and capabilities based on experience and skill levels.

This is the first in a three-part series of articles that examine C-5 TNMCM rates.

Article Acronyms

AFB--Air Force Base AFLMA--Air Force Logistics Management Agency AFSC--Air Force Specialty Code AMXS--Aircraft Maintenance Squadron ANGB--Air National Guard Base APG--Aerospace and Powerplant General CBT--Computer-Based Training CMS--Component Maintenance Squadron EMS--Equipment Maintenance Squadron ETCA--Education and Training Course Announcement LCOM--Logistics Composite Model MXG--Maintenance Group MXS--Maintenance Squadron NEP--Net Effective Personnel TDY--Temporary Duty TNMCM--Total Not Mission Capable Maintenance

End Notes

(1.) General T. Michael Moseley, CSAF's Vector: Air Mobility's Strategic Impact, 23 May 2007, [Online] Available: hnp://www.af.mil/library/ viewpoints/csaf.asp?id=324.

(2.) Honorable Michael W. Wynne and General T. Michael Moseley, "Strategic Initiatives," presentation to the House Armed Services Committee, 24 October 2007.

(3.) Michael W. Wynne, "Savings Less Than Expected in Drawdown," briefing to the Center for Strategic and Budgetary Assessments, Air Force Times, [Online] Available: www.airforcetimes.com/news/2007/ 09/airforce wynnedrawdown 070924, accessed 9 September 2007.

(4.) AFI 21-101, Aircraft and Equipment Maintenance Management, HQ USAF/A4MM, 29 June 2006, 28.

(5.) Study team notes from 439 MXG daily production meeting, Westover ARB, 12 December 2006.

(6.) Study team notes from meeting with 436 MXG/CD, Dover AFB, 8 January 2007.

(7.) Study team notes from meeting with 105 MXG/CC, Stewart ANGB, 18 January 2007.

(8.) Carl J. Dahlman, Robert Kernchner, and Davis E. Thaler, Setting Requirements for Maintenance Manpower in the US Air Force, Santa Monica, California: RAND Corporation, 2002, 136.

(9.) J.R.T. Arnold and S. Chapman, Introduction to Materials Management, 5th ed., Pearson Education, 2003, 244.

(10.) Herbert Hecht, Systems Reliability and Failure Prevention, Norwood, MA: Artech House Inc., 2004.

(11.) John G. Drew, Kristin F. Lynch, Jim Masters, Robert S. Tripp, and Charles Robert Roll, Jr., Maintenance Options for Meeting Alternative Active Associate Unit Flying Requirements, Santa Monica, California: RAND Corporation, MG-611-AF, 2008.

(12.) Ibid.

(13.) Ibid.

(14.) Ibid.

(15.) Ibid.

(16.) Dahlman, et. al., 132.

(17.) This figure represents data from the 436 AMXS for March-April 2007.

(18.) "Ancillary Training," Airman's Roll Call, [Online] Available: http://www.af.mil/shared/media/document/AFD-070209-083.pdf, accessed 9 February 2007.

(19.) Ibid.

(20.) Study team notes from meeting with 436 MOS Supervision, 9 January 2007.

(21.) 436 AMXS/MXAA, Dover AFB, March--April 2007.

(22.) "Education and Training Course Announcement," ETCA Web site, [Online] Available: https://etca.randolph.af.mil/, accessed 21 March 2007.

(23.) Ibid.

(24.) US Office of Personnel Management, "Federal Holidays," [Online] Available: http://www.opm.gov/fedhol/, 11 April 2007.

(25.) It should be noted that the study team performed sensitivity analysis on the last three assumptions. See Table 3.

(26.) 436 AMXS/MXAA.

(27.) Data for 12 April 2007, 436 AMXS/MXAA, Dover AFB.

(28.) G/C is alternatively known as Automatic Flight Controls & Instruments.

(29.) 436 AMXS/MXAA.

(30.) Ibid.

(31.) Air Force Personnel Center, data pull, 27 March 2007.

(32.) Values in Table 7 are rounded to nearest whole number.

Jeremy A. Howe, Whirlpool Corporation Benjamin A. Thoele, FitWit Foundation Scotty A. Pendley, Captain, USAF, AFLMA Anthony F. Antoline, Major, USAF, AFLMA Roger D. Golden, DPA, AFLMA

Jeremy A. Howe is currently employed with the Whirlpool Corporation, Corporate Headquarters, as the Manager, North American Region Supply Chain Metrics Team. He previously worked as a Captain in the Air Force Logistics Management Agency as Chief, Munitions Analysis.

Benjamin A. Thoele is currently the Executive Director of the FitWit Foundation in Atlanta, Georgia. He previously worked as a Captain in the Air Force Logistics Management Agency as an operations researcher and Chief, Logistics Analysis.

Major Scotty A. Pendley is currently the Chief, Maintenance Studies Branch, Logistics Innovation Studies Division, Air Force Logistics Management Agency.

Major Anthony F. Antoline is currently the Chief, Logistics Logistics Transformation Division, Air Force Logistics Management Agency.

Roger D. Golden is the Director, Air Force Logistics Management Agency.

Who bravely dares must sometimes risk a fall.

--Tobias George Smollett

Figure 2. 436 AMXS APG Day Shift Personnel Availability
Snapshot (27)

                                     3-Level   5-Level   7-Level

Assigned                                32        28        22
Temporary Duty                                     6         4
Qualification and Training Program       9
Detail                                   2         3         2
Leave                                    2         3         2
Scheduled Off Day                        2         1         2
Medical Profile                                    2         1
Part-day Appointment                     1         1         1
Full-day Appointment                                         2
Compensatory Off Day                                         1
Flying Crew Chief Mission                          1
Out Processing                                     1
Permanent Change of Assignment                     1
Field Training Detachment Course                   1
First Term Airmen's Center               1
Bay Orderly                              1
Available                               14         8         7

                                     Total   % of Total

Assigned                              82         100%
Temporary Duty                        10          12%
Qualification and Training Program     9          11%
Detail                                 7           9%
Leave                                  7           9%
Scheduled Off Day                      5           6%
Medical Profile                        3           4%
Part-day Appointment                   3           4%
Full-day Appointment                   2           2%
Compensatory Off Day                   1           1%
Flying Crew Chief Mission              1           1%
Out Processing                         1           1%
Permanent Change of Assignment         1           1%
Field Training Detachment Course       1           1%
First Term Airmen's Center             1           1%
Bay Orderly                            1           1%
Available                             29          35%

Table 1. Productivity Factors (15)

Technician Category            Productivity Factor

Non-manager 7-levels           100%
Non-manager 7-level trainers    85%
5-levels                       100%
5-level trainers                85%
3-levels                        40%

Table 2. Best Estimate of CBT and Ancillary Training Time Requirements

Technician         Hours per Year      Hours per
                                         Workday

3-level                    132.10           0.60
Formula          1.2 ([M.sub.o] +   (Hrs/yr)/220
                  (0.1VJ[S.sub.o]
5- / 7-level                92.17           0.42
Formula           1.2([M.sub.a] +   (Hrs/yr)/220
               (0.1(VJ[S.sub.o] +
                    VJ[S.sub.a]))

Technician             Percentage of          Minutes per
                      8-Hour Workday              Workday

3-level                        7.51%                36.03
Formula        (Hrs/workday)/8 * 100   (Hrs/workday) * 60

5- / 7-level                   5.24%                 25.1
Formula        (Hrs/workday/8) * 100   (Hrs/workday) * 60

Table 3. CBT and Ancillary Training Factor Sensitivity Analysis

                       3-Levels
                % Travel/Setu Multiplier

% V/JST             1    1.05     1.1    1.15     1.2    1.25

0.00            0.942   0.939   0.937   0.934   0.931   0.928
0.05            0.940   0.937   0.934   0.931   0.928   0.925
0.10            0.937   0.934   0.931   0.928   0.925   0.922
0.15            0.935   0.932   0.929   0.925   0.922   0.919
0.20            0.933   0.929   0.926   0.922   0.919   0.916
0.25            0.930   0.927   0.923   0.920   0.916   0.913

                    5- and 7-Levels
                % Travel/Setu Multi tier

% V/JST             1    1.05     1.1    1.15    1.20    1.25

0.00            0.962   0.960   0.958   0.956   0.954   0.952
0.05            0.959   0.957   0.955   0.953   0.951   0.949
0.10            0.956   0.954   0.952   0.950   0.948   0.945
0.15            0.954   0.951   0.949   0.947   0.944   0.942
0.20            0.951   0.948   0.946   0.944   0.941   0.939
0.25            0.948   0.946   0.943   0.940   0.938   0.935

                  Descriptive Statistics

                 Mean     Min     Max   Range

3-Level         0.928   0.913   0.942   0.030
5- and 7-Level  0.949   0.935   0.962   0.027

Table 5. 436 AMXS NEP Descriptive Statistics

411 Assigned            March 07                April 07
                Min   Max   Mean   Range   Min   Max   Mean   Range

Available        79   167   120    88      77    124   105    47
% of Assigned   19%   41%   29%    21%     19%   30%   26%    11%

411 Assigned          March-April 07
                Min   Max   Mean   Range

Available        77    167   113    90
% of Assigned   19%   41%   27%    22%

Table 6. NEP Factors

Factor         Description                                     Value

[T.sub.75]     Ancillary/CBT Factor for                        0.948
               7- and 5-levels
[A.sub.75NT]   The number of available             Varies day-to-day
               nonmanager 7-levels and
               5-levels who are not trainers
[P.sub.T]      Trainer Productivity                             0.85
[A.sub.75T]    The number of available             Varies day-to-day
               nonmanager 7-levels and
               5-levels who are trainers
[T.sub.3]      Ancillary/CBT Factor for 3-levels               0.925
[P.sub.e]      Trainee Productivity                              0.4
[A.sub.3]      The number of available 3-levels    Varies day-to-day

Table 7. Day of the Week NEP Distributions for 436 MXG (AMXS and
MXS) (32)

                      Day of the week NEP Distributions

NEP             Sun   Mon    Tue    Wed    Thu   Fri   Sat

                186   219    228    211    259   219   187
                148   209    226    219    213   182   140
                153   212    211    242    219   195   155
                188   242    289    297    245   205   169
                165   210    220    216    294   235   198
                137   186    187    195    205   175   148
                173   206    192    188    194   176   168
                167   213    201    195    183   186   174
                176   203                  185   194   180
n                 9     9      8      8      9     9     9
Min             137   186    187    188    183   175   140
Max             188   242    289    297    294   235   198
Mean            166   211    219    221    222   196   169
% of Assigned   23%   29%    30%    30%    30%   27%   23%
Range            51    56    102    109    110    59    58
Variance        300   221   1031   1241   1385   404   349
Standard Dev     17    15     32     35     37    20    19

Figure 2. 436 AMXS Availability Descriptive Statistics

411 Assigned            March 07               April 07
                Min   Max   Mean   Range   Min   Max   Mean   Range

Available       100   202    147     102   104   163   137     59
% of Assianed   24%   49%    36%     25%   25%   40%   33%    14%

411 Assigned          March-April 07
                Min   Max   Mean   Range

Available       100   202   142    102
% of Assianed   24%   49%   35%    25%