Baseline
A formally acknowledged set of information establishing a frame of reference from which deviation or departure can be measured (see also basis). The concept of a “baseline” should be thought of as a practical reaction to the observer effect1 in Physics: watching too closely impacts the work being done. With a baseline, management can permit... read more
Basis of Estimate (BoE)
The underlying logic used to estimate the resources needed to execute a contract change action (including, but not limited to, a proposal1). The BoE can be parameterized in either dollars or hours, spread over time or a sequence of program milestones. The BoE is not the estimate itself, but the methodology for arriving at the... read more
Budget
A specific amount of resource, reserved for some specific purpose. Most of the time, the “resource” is money, and the allocation is to a WBS Element. However, the term “budget” can also be used in a technical sense, referring to some run-time resource relevant to the target system (e.g., “link budget” or “weight budget”). The... read more
Chief Engineer
The individual, usually a member of management, charged with ensuring the technical integrity of a project. It used to be that there was exactly ONE Chief Engineer for any given project. More recently, we have more Chief Engineers than Carter has pills. I haven’t figured out why that happened: being a real Chief Engineer is... read more
Commercial Development
Development financed on speculation1 by the developer, so that any errors or flaws are entirely at the developer’s risk. The antithesis of Contracted Development. Footnotes “on spec”, not to be confused with “within spec” or “to spec”, both of which refer to some form of Specification or Envelope Drawing.[↩]
Complexity
That property of a system having to do with: the number of widgets in the system the number of DoF in the relationships between the widgets one or more of those widgets and the outside world the precision and/or accuracy required the rate of change during development and/or during operation the criticality or importance the... read more
Design Certification Review (DCR)
A NASA term, roughly equivalent to FCA plus PCA. NASA developmental techniques were historically geared toward mission-specific hardware, or very small production runs. The review essentially constitutes the point at which the Developer warrants (within the terms of the development contract) an entire system for the intended use.
Disposition
A decision made with respect to some formally identified, formally managed issue. The issue can be any of many forms (e.g., Review Item Discrepancy or Non-Conformance).
Full Scale Engineering Development (FSED)
A contractual phase in which a system is designed and qualified (“developed”), with the full rate production line(s) being readied as part of the same contract. Contrast with CRAD, which typically does not have the same emphasis on (at least eventual) full rate production. FCA and at least one PCA are typically included in FSED.
Functional Baseline
The complete set of functions (and their associated measures) necessary for a system to meet its intended Operational Requirements in the context of a preliminary design, formally designated as the initial technical baseline for subsequent development. In this context, “complete” is used prescriptively rather than restrictively. When complete, a hardware design will always have functions... read more
Functional Configuration Audit (FCA)
One of the most unfortunate misnomers in the System Engineering lexicon, FCA is the audit that closes the design part of development. The name traces its origin back to the concept of a Functionally Allocated Baseline.
Functionally Allocated Baseline
A follow-on to the Functional Baseline, where Its functions have been formally assigned (allocated) in the form of Performance Requirements to subordinate Configuration Items as identified during the Preliminary Design process; All other types of requirements have been allocated to the subordinate CI’s using the hierarchy established by the functional decomposition. If necessary in order... read more
Hardware Authorization Document (HAD)
In the legacy, the HAD stipulated all of the uses to which full-certification-data (e.g., part-marked as if flight hardware) hardware could be applied, authoritatively originating all effectivities for a given program. It was the ultimate source for such data on the application block of the identifying drawings. Modern practices extend this concept to software (a “Software/Hardware... read more
Imaginary Number
Two distinct definitions exist: Any number involving the square root of -1. Typically used in numerically intensive, analytically oriented things like signal processing, control theory, and electromagnetism to assist in (for example) stability analysis, but also sometimes used just to make the math work out right (which was, in fact, the original application). Schedule dates... read more
Keep the program sold
A marketing strategy having to do with protecting the life of a program in spite of the many developmental difficulties it may be facing. The strategy may, or may not, be collusively pursued by both contractor and Acquisition Customer. Sadly, this strategy is a necessary part of getting anything useful done in a bureaucratic environment,... read more
Make-or-Buy Decision
A design process, occurring early in development, assessing the relative cost effectiveness and feasibility of internal development for an item vs. external procurement of that item. The decision strongly influences how things will go afterwards, bringing substantially different skills and tools into play.
Management
In the context of System Engineering, active control based on cost, technical, or schedule status of a project. In this context, “control” means that we’re paying attention to the projected technical adequacy of a CI, when we expect to turn it over to the customer, and how much they’ll have to pay for the privilege. If it... read more
Master Verification Plan (MVP)
The intent of an MVP is to describe the broad outlines of how verification is approached on a complicated program. The benefit of having a technically competent MVP is that it can provide context for the approach, showing how the major activities relate to each other. However, MVP’s can attempt to control too much detail,... read more
MIL-STD-1521
A now-canceled standard governing the content of various technical reviews and audits. This document was the basis for PDR, CDR, and FCA for decades.
MIL-STD-499
A now-canceled standard for System Engineering Management.
Objective Requirement
Not, in fact, a requirement at all unless the customer explicitly identifies (in the SoW or T&C) some time, event, or circumstance at which it becomes mandatory, in which case they would more properly be represented by classification of the CI in question. Usually, just an indication of what the customer wishes they could have, if... read more
Physical Configuration Audit (PCA)
A formal audit establishing the ability of a manufacturing facility (or set of facilities) to acceptably produce Serial Numbers (or lots) of a design for a CI. A new PCA must be held for each line, and each time a line is restarted. The length of down time prior to such a re-start is usually... read more
Preliminary Design
The collection(s) of design features, which may or may not constitute a comprehensive design, corresponding to the development specifications authenticated at PDR and used to establish the feasibility of the Functionally Allocated Baseline established at the end of that program phase.
Preliminary Design Review (PDR)
The review (contrast with “audit”) at which it is determined that a feasible allocation of development requirements can be made to an identified set of Configuration Items, such that a Functional Baseline can be implemented with reasonable cost and schedule. The review may occur over an extended period of time, culminating with authentication of the development specifications.... read more
Prime Contract
A contract let by the Acquisition Customer for an entire project. This type of contract is, therefore, distinct from all sub-contracts let by the Prime Contractor or any sub-contractor thereof. All money for the project tracks back to one or more Prime Contracts. It is possible for a single sub-contract to trace to more than... read more
Prime Item
Anecdotally, a CEI on a Prime Contract and, therefore, the subject of a Type B1 specification in accordance with MIL-STD-490. Lower-order CI’s could also be CEI’s (especially late in the contract, as maintenance items were formally identified), but these (the Prime Items) were considered the heavy-hitters.
Process
In the vernacular, a repeatable activity or repeatable set of interrelated activities that collectively create a set of one or more outputs from a set of one or more inputs. A set (which may, or may not, include parallelization) of steps (tasks or logical instructions) not necessarily having a defined, internally managed set of terminating criteria.... read more
Product Line
A group1 of related Products. The relationship may be one of design derivation or evolution, similarity in technology, collocation of fabrication facilities, or any other factor causing a particular organization to designate them for collective management. Footnotes Which might be temporally sequential[↩]
Program
A collection of one or more contracts being managed at a single site, typically sharing a common customer, technology, and/or product line, and usually under the supervision of a single individual (a “Program Manager”).
Ramp-up
The personnel profile during a project’s startup transient. The entire roll-off discussion also applies here, but inversely.
Recovery Plan
The plan written when a failure to hold the published schedule can no longer be denied. The objective of a recovery plan is to return to the published schedule at some milestone defined thereupon, executing in accordance with the published plan thereafter. Once a project reaches a critical mass of recovery plans1, the original schedule... read more
Review
A review is a formal inspection of developmental progress, generally for the purpose of obtaining concurrence from an Acquisition Customer that work done to date indicates that the final product is reasonably expected to suit their intended purpose. Such in-process meetings functionally serve to reduce anxiety on the part of the customer with regard to... read more
Review Item Discrepancy (RID)
An issue, found during a review (e.g., SDR, PDR, or CDR) or audit (e.g., FCA or PCA), with regard to whether or not some requirement has been met by some design or work submitted with regard to that design.
Roll-off
Roll-off describes the desired shape of the personnel resource profile for a project showing how people are re-deployed as a project winds down: we want the profile to decline gradually enough for the people to be absorbed by other on-going projects, avoiding a lay-off situation. When the “roll-off” is precipitous, we have to quickly find... read more
Schedule
The network of dated, resource-loaded tasks and task precedence relationships to be ignored during execution of a project.
Statement of Work (SoW)
Make your life simple. Go read MIL-HDBK-245. Unless otherwise specified in the contract, the precedence of a SoW is lower than that of the T&C, but higher than that of a Specification.
Stockable Part
A part that is (or can be) be manufactured in advance of need and stored for subsequent sale as being interchangeable with any other of the same part number.
Subcontract
A contract that is contractually and financially subordinate to some other contract (e.g., a Prime Contract) that governs its objectives, practices, and disbursement of funds.
Supplier
A source of hardware, software, or services that can generally be exchanged for currency.
System Design Review (SDR)
In the legacy a review held to determine whether “big picture” requirements were individually and collectively feasible to a degree sufficient to warrant expenditure of further government funds. SDR usually corresponded to an A-Spec, and was therefore a government internal event. More recently, it is something else altogether.
System Engineering “V”
A crude depiction of the notion that, as time goes by, System Engineering practices deal with smaller and smaller pieces of the system…but, eventually, they start stitching things back into bigger chunks. I have significant issues with the “V” notion as a primary training tool and process descriptor because I don’t think it describes the... read more
System Management Plan (SMP)
A subset of the information of a SEMP, excluding the technically relevant aspects of management and, therefore, having less project specificity. That is, it pretty much leaves Engineering out of things.
System Requirements Review (SRR)
In legacy practices, a review held within the government to determine whether A-specs adequately assigned technical requirements to the various government entities that would over-see the contractors of a large project (which may, or may not, be part of a single government program). In modern uses, an excuse to make it look as if we... read more
Systems Engineering Management Plan (SEMP)
A SEMP is a project-specific plan that sequences the important activities of a program, with particular emphasis on provisions for oversight and mid-course correction. In this context, “sequencing” means that the SEMP might lay constraints on certain activities such that they are predicated on successful progress on other activities. Such constraint may be of any... read more
Technical Performance Measurement/Monitoring (TPM)
TPM is a sometimes elaborate process used to identify important quantitative technical characteristics and features of the system, and report them to management on a regular basis. For each characteristic, a plan is usually developed to show how its predicted (or estimated) value will improve over the course of development, and “trigger” values will be... read more
Technical Reviews and Audits
Any review or audit having technical material (as opposed to cost or schedule) as its subject. For any given developmental project, these reviews are organized according to the hierarchy of CI’s. Legacy practices in this regard for DoD development were governed by MIL-STD-1521B, which is worth a read just to understand what they had in... read more
Terms and Conditions (T&C)
Of the three things that provide direction to developers, the T&C have the highest legal precedence, and can over-ride all other considerations. The T&C are found directly in the contract. The term is sometimes completed with “…of the contract” in order to be explicit and precise. It may be sad, but after all is said... read more
Verification Analysis Cycle (VAC)
The project-specific sequence of analyses repeated during development as a leading indicator of successful compliance with requirements. Ideally, the VAC should use analysis methods and tools that are different than those used in support of design in order to minimize susceptibility to systemic errors, but that can really drive a project’s cost. Contrast with DAC... read more
Vicissitudes of Developmental Fortune
Issues will crop up that were not foreseen by the SEMP/SMP/MVP or Recovery Plan of the Week. “It seemed like a good idea when we wrote the requirements. It just didn’t work very well.” New technologies and new uses of existing technologies will turn out to need restrictive or integrating requirements that were not understood... read more
WBS Element
Work Breakdown Structure (WBS)
A hierarchical organization of all the work (effort) required to complete a project. See MIL-STD-881 and follow it. It is conceptually complete and cogent. It is sometimes supposed that a WBS should follow the contractor’s organizational structure (hierarchy of managers), because it is easier to see how the tasks rack-and-stack to the organization. The notion... read more