Systems Engineering · PDF file · 2015-12-03meet a requirement. ... Systems Engineering The Government's Responsibilities ... (DT&E) • Government establishes system-level performance

Skip NavigationGlossary Acronyms Resources Plugins He

D

Systems EngineeringSystems Engineering

page 1 of 31

Long Description

Title screen for Module 4, Lesson 1: Technical Management, Systems Engineering containing three photos: one of business people reviewing information on a laptop, a DHS truck, and scales.


Introduction

Welcome to the Systems Engineering lesson. Since there are many acquisition career fields besides engineering, you may not be familiar with the discipline or its vocabulary. This lesson will give you a high-level overview of each. Systems engineering is a problem-solving approach to designing and developing a solution to meet a requirement.

You'll be introduced to the following concepts in this lesson:

• The Systems Engineering Life Cycle (SELC) and its associated technical reviews

• The Systems Engineering (SE) process

• The tools engineers use to manage the process and control the output

To print this lesson, select print.


This lesson covers the portion of the SE process that translates needs and requirements into a design solution. It does not cover turning the design solution into a product or verifying and validating that the product meets the needs and satisfies the requirements.

page 2 of 31


Learning Objectives

Upon completion of this lesson, you will be able to:

• Differentiate between the roles and responsibilities of the Government and the contractor in the Systems Engineering (SE) process

• Identify three steps of the SE process

• Identify key technical management processes and tools used in the SE process

• Identify the characteristics of a balanced systems design


page 3 of 31


Systems Engineering Life Cycle

DHS has established a Systems Engineering Life Cycle (SELC) to guide the technical management side of acquisition programs. The SELC runs in parallel with the Acquisition Life Cycle Framework (ALF), starting during the Analyze/Select Phase and continuing through system disposal.

D

Click here to view an enlargement and learn more.

The intent of the SELC is to provide program managers with sound, repeatable engineering processes that help deliver capabilities to users efficiently and effectively.


This lesson focuses on the Systems Engineering (SE) process followed during the first half of the SELC, during the lead up to the Critical Design Review (CDR), at which time the design is complete and ready for development. This lesson also includes high-level descriptions of each SELC review.

page 4 of 31

Long Description

The ALF consists of four phases: Need, Analyze/Select, Obtain, and Produce/Deploy/Support. Included in the four phases are six acquisition decision events (ADEs), numbered: 0, 1, 2A, 2B, 2C, and 3.

The SELC runs in parallel with the ALF and consists of one recommended, and nine major activities: Needs Analysis (a recommended pre-SELC activity), Solution Engineering, Planning, Requirements Definition, Design, Development, Integration and Test (I&T), Implementation, Operations and Maintenance (O&M), and Disposition. Included are eleven technical reviews: SPR, SER, PPR, SDR, PDR, CDR, IRR, PRR, OTRR, ORR, and PIR.

The SELC Solution Engineering activity aligns with the ALF Analyze/Select phase. The SELC major activities Planning, Requirements Definition, Design, Development, Integration and Test (I&T), and Implementation align with the ALF Obtain phase. SELC major activities are often iterative or concurrent in nature and are not strictly performed in a stepwise or sequential manor, hence the recursive loop shown for Requirements Definition, Design, Development and Integration and Test. SELC major activities Operations and Maintenance and Disposition align with the ALF Produce/Deploy/Support phase.


A Technical Management Partnership

Since DHS does not have all the necessary resources, industrial capability, and engineering talent within its organization, it must contract out the majority of its development work. The Government and the prime contractor work together to transform an identified mission need into a fielded system through SE.

Select each tab for additional information.


page 5 of 31

The Contractor's Responsibilities

In this technical management partnership, the Government's responsibilities are:

• Translate the user’s operational need into a system performance specification

• Establish system-level performance thresholds and objectives

• Monitor technical progress

• Review and approve the contractor’s technical deliverables

• Conduct Operational Test and Evaluation (OT&E)

The Government's Responsibilities

SE

Systems Engineering

The Government's Responsibilities

In this technical management partnership, the Government's responsibilities are:

• Translate the user’s operational need into a system performance specification• Establish system-level performance thresholds and objectives• Monitor technical progress• Review and approve the contractor’s technical deliverables• Conduct Operational Test and Evaluation (OT&E)

The Contractor's Responsibilities

In this technical management partnership, the contractor's responsibilities are:

• Translate system performance specification into technical design specifications• Allocate system performance thresholds and objectives to subsystems and components• Manage the design progress using its own internal standards and processes• Validate internal and subcontractor performance• Conduct Developmental Test and Evaluation (DT&E)


Knowledge Check

For each activity listed below, choose the responsible party (the Government or the contractor) from the drop-down list provided. When you have selected the responsible party for each activity, select Submit.

Conducts Developmental Test and Evaluation (DT&E)Contractor

Establishes system-level performance thresholds and objectivesGovernment

Conducts Operational Test and Evaluation (OT&E)Government

Translates system performance specification into technical design specificationsContractor

Allocates system performance thresholds and objectives to subsystems and componentsContractor

Translates user’s operational need into a system performance specificationGovernment

Show my answer


page 6 of 31

• Contractor conducts Developmental Test and Evaluation (DT&E)• Government establishes system-level performance thresholds and objectives• Government conducts Operational Test and Evaluation (OT&E)• Contractor translates system performance specification into technical design specifications• Contractor allocates system performance thresholds and objectives to subsystems and components• Government translates user's operational need into a system performance specification


Recap: Introduction

Review the key concepts introduced in this topic:

• Systems Engineering (SE) is a problem-solving approach to designing and developing a solution to meet arequirement.

• DHS has established a Systems Engineering Life Cycle (SELC) to guide the technical management side ofacquisition programs.

• The SELC runs in parallel with the Acquisition Life Cycle Framework (ALF), starting during theAnalyze/Select Phase and continuing through system disposal.

• The Government and the prime contractor work together to transform an identified mission need into afielded system through systems engineering.

The next topic is The Systems Engineering Process.


page 7 of 31


Introduction to the Systems Engineering Process

Three steps of the Systems Engineering (SE) process transform a user’s requirements into a description of a solution to meet those requirements. The inputs to the process are the user’s performance requirements and any constraints that affect the output—funding, operational issues, environmental considerations, etc.

D

The output of the process is a system design, documented in the form of specifications, technical drawings, and other related data. This topic introduces the three steps and the review loops that help ensure success.


page 8 of 31

Long Description

This diagram depicts the three step SE process. The inputs to the process are requirements and constraints, represented by an arrow pointing to the right into step one.

The three steps are boxes labeled Requirements Analysis, Functional Analysis, and Design Synthesis. Between Step 2, Functional Analysis, and Step 1, Requirements Analysis, is the Requirements Loop.

Between Step 3, Design Synthesis, and Step 2, Functional Analysis, is the Design Loop. Between Step 3, Design Synthesis, and Step 1, Requirements Analysis, is the Verification Loop, also known as Test & Evaluation.

Technical Management Processes/Tools are used to manage, measure, and guide each step. The outputs of the SE Process are the specifications, drawings, and technical data the design comprises.


T&D

FEMA Example


page 9 of 31

Transcript and Description

[Rachel pointing to the systems engineering process]

Narrator: As we walk through the SE process, we’ll use an example to illustrate each step.

[FEMA team searching a debris field]

Narrator: Federal Emergency Management Agency (FEMA) needs to improve its ability to transport response teams to the scenes of disasters.

[Rachel and FEMA team member]

Narrator: Disaster response teams need to be able to traverse up to 50 kilometers within 90 minutes of dispatch, while remaining in constant communication throughout the trip.

[Rachel and a FEMA command vehicle]

Narrator: We don’t know yet what form this transport will take. It could be an existing commercial or government vehicle, a modification to an existing vehicle, or a newly designed vehicle.

[Rachel pointing to the SE process diagram]

Narrator: Let’s see how the SE process can be used to solve this problem.


Step 1: Requirements Analysis

Step 1 is Requirements Analysis. The goal of this first step is to fully understand the user's requirement. Systems engineers ask users lots of questions to help clarify and refine their requirements before providing a solution.

D

Here are some examples of questions engineers ask users to better understand their requirements:

• What is the system supposed to do?

• Where will the system be used?

• Under what conditions will the system be used?

• Who will use it?

• How often?

• How long?

The output of requirements analysis is a description of what the system is supposed to do, how well it must do it, and the conditions under which it must operate.


page 10 of 31

Long Description

This diagram depicts the three step systems engineering process. In this instance of the diagram, the first step, Requirements Analysis, is highlighted. The inputs to the process are requirements and constraints, represented by an arrow pointing to the right into step one. The three steps are boxes labeled Requirements Analysis, Functional Analysis, and Design Synthesis. Between Step 2, Functional Analysis, and Step 1, Requirements Analysis, is the Requirements loop. Between Step 3, Design Synthesis, and Step 2, Functional Analysis, is the Design Loop.

Between Step 3, Design Synthesis, and Step 1, Requirements Analysis, is the Verification Loop, also known as Test & Evaluation. Technical Management Processes/Tools are used to manage, measure, and guide each step. The outputs of the SE Process are the specifications, drawings, and technical data the design comprises.


Requirements:

• Transport a team

• Over a distance of 50 km

• Within 90 minutes

• Maintain communication in transit

Knowledge Check: FEMA Transport, Step 1

The list on the right summarizes what we know about Federal Emergency Management Agency (FEMA) requirements.

Put yourself in the position of the systems engineer conducting a requirements analysis. In the field provided below, type at least five questions that you will need the answers to before you can design a solution to FEMA's requirements.

Type your response in the field below. When you are finished, select Submit.

Submit

Here are some of the questions you may have identified:

• How many people are on a team?

• What kind of terrain must be traversed?

• How much equipment and gear will the team require?

• Will the team be making a one way trip or a round trip?

• Will the team be traveling both during the day andnight?

• Under what weather conditions will the team betraveling?

• Who will operate the transport?

• With whom will the team need to communicate andhow?



Step 2: Functional Analysis/Allocation

Step 2 is Functional Analysis/Allocation. The goal of this step is to identify the functions the system must perform to satisfy the requirements. In other words, to answer the question, "How will the system meet the user's requirements?"

D

During Functional Analysis/Allocation, system engineers break down high-level functions (like fly) into lower-level sub-functions (like launch, cruise, land), from which a physical solution can be designed. Functions and sub-functions are usually expressed as verbs that answer the question, "How will the system satisfy requirement 'X'?" Then they allocate individual performance requirements to those functions and sub-functions.

Example System: Aircraft

Function: Fly

Sub-functions: Launch Cruise Land

Allocated Requirements: Launch from aircraft carrier Range of 1600 nmi Land on aircraft carrier

A functional analysis diagram or logical architecture may be developed to capture the results of the functional analysis.


page 12 of 31

Long Description

This diagram depicts the three step SE process. In this instance of the diagram, the second step, Functional Analysis/Allocation, is highlighted. The inputs to the process are requirements and constraints, represented by an

arrow pointing to the right into step one. The three steps are boxes labeled Requirements Analysis, Functional Analysis, and Design Synthesis. Between Step 2, Functional Analysis, and Step 1, Requirements Analysis, is the Requirements loop. Between Step 3, Design Synthesis, and Step 2, Functional Analysis, is the Design Loop. Between Step 3, Design Synthesis, and Step 1, Requirements Analysis, is the Verification Loop, also known as Test & Evaluation. Technical Management Processes/Tools are used to manage, measure, and guide each step. The outputs of the SE Process are the specifications, drawings, and technical data the design comprises.


FEMA Transport: Step 2

The diagram below shows the beginning of a high-level functional analysis/allocation for FEMA team transport. Put yourself in the position of the systems engineer conducting the Functional Analysis, beginning to break the system down into functions and sub-functions and allocate performance requirements.

Select each level (system, functions, sub-functions, allocated requirement) in the diagram below for more information.

D


page 13 of 31

Long Description

This is an excerpt from a Functional Analysis diagram for the fictional FEMA team transport. It has four levels. The top level represents the entire system and is labeled FEMA Team Transport. The next level down represents some ofthe systems main functions: transport and communicate. The next level down represents some of the sub-functions of the function transport: load, start, move, stop, and unload. In the fourth and bottom level, the requirement for the team to arrive at its destination within 90 minutes has been allocated to those sub-functions: an estimate 10 minutes to load, 2 minutes to startup the vehicle and its communications equipment, 72 minutes to move from point of origin to destination, 1 minute to stop the vehicle, and 5 minutes to unload the team and its equipment.

System

Start with the entire system, and begin identifying the functions it will have to perform to satisfy the users\' performance requirements.

Functions

Two of those functions are to transport the team to a disaster site and to allow them to communicate constantly during transit.

Subfunctions

Next, begin to break those functions down into subfunctions. Taking the transport function as an example, the vehicle will have to be loaded with personnel and equipment and started (and ostensibly the communications equipment initialized). It will have to move from its point of origin to the disaster site. Once there, it will have to stop and park, and the personnel and equipment will have to be unloaded.

Allocated Requirement

Finally, allocate the system\'s performance requirements to the functions and sub-functions. For example, the team has to reach its destination within 90 minutes. If it takes approximately 10 minutes to load the vehicle, 2 minutes to start it up and initialize the communications equipment, 1 minute to stop, and 5 minutes to unload, that leaves 72 minutes for moving from point A to point B. From this estimate, we can derive the average speed it would need to travel based on the distance requirement of 50 km. In this case, 41.67 km/hr.


Requirements Loop

Before Step 3, system engineers take the time to ensure that their analysis is correct. They verify that every requirement is covered by at least one function; and every function is linked to at least one requirement (otherwise it's unnecessary). This is called the "Requirements Loop."

D

The Requirements Loop is the first of three traceability loops that are vital to the success of the design.


page 14 of 31

Long Description

This diagram depicts the three step SE process. In this instance of the diagram, the Requirements Loop between steps one and two is highlighted, and elaborated with the following two bullet points: "Ensure all requirements are addressed" and "Ensure all functions are justified by a valid requirement." The inputs to the process are requirementsand constraints, represented by an arrow pointing to the right into step one. The three steps are boxes labeled Requirements Analysis, Functional Analysis, and Design Synthesis. Between Step 2, Functional Analysis, and Step 1, Requirements Analysis, is the Requirements Loop. Between Step 3, Design Synthesis, and Step 2, Functional Analysis, is the Design Loop. Between Step 3, Design Synthesis, and Step 1, Requirements Analysis, is the Verification Loop, also known as Test & Evaluation. Technical Management Processes/Tools are used to manage, measure, and guide each step. The outputs of the SE Process are the specifications, drawings, and technical data the design comprises.


Step 3: Design Synthesis

Step 3 is Design Synthesis. The goal of this step is to define the physical architecture of the system—the hardware and software components that will be built and/or assembled to perform the functions needed to meet the requirements.

D

During Design Synthesis, systems engineers attempt to answer the question, "What will perform function 'X'?" with a noun. Those nouns become part of the system architecture, which is the output of the Design Synthesis.


page 15 of 31

Long Description

This diagram depicts the three step SE process. In this instance, the third step, Design Synthesis, is highlighted. The inputs to the process are requirements and constraints, represented by an arrow pointing to the right into step one. The three steps are boxes labeled Requirements Analysis, Functional Analysis, and Design Synthesis. Between Step 2, Functional Analysis, and Step 1, Requirements Analysis, is the Requirements Loop. Between Step 3, Design Synthesis, and Step 2, Functional Analysis, is the Design Loop. Between Step 3, Design Synthesis, and Step 1, Requirements Analysis, is the Verification Loop, also known as Test & Evaluation. Technical Management Processes/Tools are used to manage, measure, and guide each step. The outputs of the SE Process are the specifications, drawings, and technical data the design comprises. For more information, reference the Technical Review Guide on the SE COE site.


FEMA Transport: High-Level Architecture

Let's take a look at a high-level excerpt from a systems architecture for our FEMA Team Transport example. From this point of view, the example may seem quite simple, but if systems engineers had to build this transport from scratch, they would take a methodical, comprehensive approach to system design.

Select each section of the design below for more information.

D

Each system is broken down into subsystems. Each subsystem in turn is broken down into components. Components are broken down into assemblies, assemblies into subassemblies, and subassemblies into parts until the entire system is included in an initial design.


page 16 of 31

Long Description

This is a basic, high-level system architecture diagram for the FEMA Team Transport, arranged in a hierarchical configuration, like an organizational chart. At the top level is the Transport itself. It’s broken down into major subsystems or components: body, engine, wheels, brakes, and communications. Body is broken down further into doors, seats, etc. The engine is broken down further into spark plugs, valves, pistons, etc. The wheels are broken down further into rims, tires, etc. The brakes are broken down further into drums, pads, shoes, etc. Communications is broken down further into radio, satellite link, etc.

System

As before, the top level represents the entire system.

Major Subsystems

Designers start with the major hardware and software subsystems needed to perform the functions identified during Functional Analysis (Step 2), and then break them down into lower levels of detail.

The Body Subsystem

The vehicle needs a frame, doors, and seats for personnel.

The Engine Subsystem

The engine must include certain basic parts, like spark plugs, valves, and pistons.

The Wheels Subsystem

The wheels would, of course, need tires on them, and rims.

The Brakes Subsystem

The braking system would include drums, pads, and shoes.

The Communications Subsystem

The communications system would include at least a radio and a satellite link of some sort.

FEMA

Federal Emergency Management Agency


Design Loop

After Design Synthesis, system engineers take the time to perform two additional traceability loops: the Design Loop and the Verification Loop.

First, they compare the required functions to the hardware and software components in the system architecture to ensure all functions are covered by at least one component, and that there is no unjustified redundancy.

D

In other words, they verify that every function identified in Step 2 is performed by at least one component of the physical architecture identified in Step 3. They also ensure each component of the physical architecture is traceable back to at least one valid functional requirement. This analysis is called the Design Loop.


page 17 of 31

Long Description

This diagram depicts the three step SE process. In this instance, the Design Loop between steps two and three is highlighted, and elaborated with the following two bullet points: "Ensure all functions are addressed by at least one hardware or software element" and "Ensure all elements of the physical architecture are justified by a valid functional requirement." The inputs to the process are requirements and constraints, represented by an arrow pointing to the right into step one. The three steps are boxes labeled Requirements Analysis, Functional Analysis, and Design Synthesis. Between Step 2, Functional Analysis, and Step 1, Requirements Analysis, is the RequirementsLoop. Between Step 3, Design Synthesis, and Step 2, Functional Analysis, is the Design Loop. Between Step 3, Design Synthesis, and Step 1, Requirements Analysis, is the Verification Loop, also known as Test & Evaluation. Technical Management Processes/Tools are used to manage, measure, and guide each step. The outputs of the SE Process are the specifications, drawings, and technical data the design comprises.


Knowledge Check: FEMA Transport, Design Loop

The lists below represent functions of the FEMA Transport identified during Functional Analysis/Allocation (Step 2) and components of the systems architecture identified during Design Synthesis (Step 3). Put yourself in the position of the systems engineer following the Design Loop. Your job is to ensure each component of the physical architecture is traceable back to at least one valid functional requirement.

For each component of the physical architecture below, select the functional requirement it traces back to from the drop-down list provided. When you are finished, select Submit.

DoorsLoad/Unload

EngineStart

WheelsMove

BrakesStop

Radio TransmitterSend

Satellite ReceiverReceive

Show my answer


page 18 of 31

• Doors: Load/Unload• Engine: Start• Wheels: Move• Brakes: Stop• Radio Transmitter: Send• Satellite Receiver: Receive


Verification Loop

Second, the systems engineer needs to verify that the solution, as designed, satisfies the user's requirements. This step is called the Verification Loop.

D

There are many different ways to accomplish this formal verification—inspections, modeling and simulation, etc.—but the most common method is through rigorous Test and Evaluation (T&E).


page 19 of 31

Long Description

This diagram depicts the three step SE process. In this instance, the Verification Loop between steps three and one ishighlighted, and elaborated with the following two bullet points: "Ensure the system satisfies the requirements" and "Verification can be accomplished by inspections, simulations, and tests." The inputs to the process are requirementsand constraints, represented by an arrow pointing to the right into step one. The three steps are boxes labeled Requirements Analysis, Functional Analysis, and Design Synthesis. Between Step 2, Functional Analysis, and Step 1, Requirements Analysis, is the Requirements Loop. Between Step 3, Design Synthesis, and Step 2, Functional Analysis, is the Design Loop. Between Step 3, Design Synthesis, and Step 1, Requirements Analysis, is the Verification Loop, also known as Test & Evaluation. Technical Management Processes/Tools are used to manage, measure, and guide each step. The outputs of the SE Process are the specifications, drawings, and technical data the design comprises.


Knowledge Check

For each question below, select the corresponding Systems Engineering Process step or loop that answers the question from the drop-down list provided. When you are finished, select Submit.

What must the system do, how well, and under what conditions?Requirements Analysis

How will the system satisfy requirement "X"?Functional Analysis/Allocation

Is every requirement covered by at least one function, and every function linked to at least one requirement?Requirements Loop

What component will perform function "X"?Design Synthesis

Is every function covered by at least one component, and every component linked to at least one function?Design Loop

Does the system satisfy the requirements?Verification Loop

Show my answer


page 20 of 31

• What must the system do, how well, and under what conditions? Requirements Analysis• How will the system satisfy requirement "X"? Functional Analysis/Allocation• Is every requirement covered by at least one function, and every function linked to at least one requirement? Requirements Loop• What component will perform function "X"? Design Synthesis• Is every function covered by at least one component, and every component linked to at least one function? Design Loop• Does the system satisfy the requirements? Verification Loop


The output of the SE process is a description of the system, which is elaborated to greater and greater levels of detail as the system is developed. This description can take the form of system performance specifications, technical specifications, drawings, technical data, and configuration baselines.

A "configuration" is simply a description of an item in terms of its function, performance, physical attributes, and interfaces. A "baseline" is a standard against which things are compared. A configuration baseline is a documentation package for a design that is used as a starting point from which to make changes. Once a configuration baseline is established, that design is "frozen," and any changes to it must follow a very formal process.

The configuration baseline evolves over time, as shown in the graphic. It’s important to stabilize requirements at one level before getting too far into the next level!

Select each element of the diagram for more information.

Systems Engineering Output


page 21 of 31

Functional Baseline

Early on in the process, the Government establishes and controls the functional baseline, (i.e., what the system must do to satisfy the users’ requirements).

Allocated Baseline

The allocated baseline captures all of the hardware, software, subsystems, and interfaces needed to perform the required functions. The contractor controls the allocated and lower-level baselines.

Development Baseline(s)

Development baseline(s) may be established at key milestones during development. Each development baseline documents more of the entire product, and it is tested as an interim, in-progress version of the system.

Product Baseline

Finally, the products and processes necessary to produce the components of each item in the design are assembled into a product baseline, which should be established by the Critical Design Review (CDR). An example would be allthe documentation about the design of the current Toyota Camry (as distinguished from the previous model).

SE

Systems Engineering


Recap: The Systems Engineering Process

Review the key concepts introduced in this topic:

• The three-step Systems Engineering (SE) process transforms a user’s requirements into a description of asolution to meet those requirements.

• The three steps of the process are: 1) Requirements Analysis, 2) Functional Analysis/Allocation, and 3)Design Synthesis.

• There are three traceability loops between the steps that are vital to the success of the design: theRequirements Loop (traces the functions identified during functional analysis/allocation back to therequirements), the Design Loop (traces the components of the system architecture back to the functionalanalysis/allocation), and the Verification Loop (formal Test and Evaluation [T&E]).

• The output of the SE process is a description of the system, which is elaborated to greater levels of detailas the system evolves through development.

The next topic is Technical Management Processes and Tools.


page 22 of 31


Introduction to Technical Management Processes and Tools

Throughout the three steps, systems engineers use a variety of technical management processes and tools to help them make decisions, track their progress, and control the output of the process.

D

For example, engineers use Work Breakdown Structures (WBSs) as technical management frameworks. They use modeling during design, and they use simulation to supplement developmental testing. They use trade studies to help make tough choices between design alternatives and risk management to improve the odds their designs are successful.

You'll be introduced to the following technical management processes and tools in this topic:

• Configuration Management (CM)

• Technical performance measures

• The Technical Reviews of the Systems Engineering Life Cycle (SELC)


page 23 of 31

Long Description

This diagram depicts the three step SE process. In this instance, the Technical Management Processes and Tools thatinteract with all three steps are highlighted. The inputs to the process are requirements and constraints, represented by an arrow pointing to the right into step one. The three steps are boxes labeled Requirements Analysis, Functional Analysis, and Design Synthesis. Between Step 2, Functional Analysis, and Step 1, Requirements Analysis, is the Requirements Loop. Between Step 3, Design Synthesis, and Step 2, Functional Analysis, is the Design Loop. Between Step 3, Design Synthesis, and Step 1, Requirements Analysis, is the Verification Loop, also known as Test

& Evaluation. Technical Management Processes/Tools are used to manage, measure, and guide each step. The outputs of the SE Process are the specifications, drawings, and technical data the design comprises.


Configuration Management

Configuration Management (CM) is the process systems engineers use to track a system's design evolution. Remember, a "configuration" is simply a description of an item in terms of its function, physical attributes, or interfaces.

CM involves four functions:

1. Identify configuration baselines.

2. Control Engineering Change Proposals (ECPs), or proposed changes to the baseline.

3. Track, or maintain a Status Accounting of, changes made to the baseline.

4. Audit the functional and physical configurations to verify the design meets the user's requirements.

Robust CM ensures designs trace back to requirements, interfaces are well-defined and understood, design changes are controlled and documented, and the product remains consistent with its supporting documentation. CM is the heart of systems engineering; it’s how system engineers ensure the many people working together to develop a complex system remain on the same page.


page 24 of 31


Technical Performance Measures

T&D


page 25 of 31

Transcript and Description

Narrator: Technical performance measures are another tool in a system engineer\'s process management toolbox.

[Close-up view of a simple line graph plotting speed over time, an objective line, and a threshold line. Data fills in gradually as narrator explains the data] Narrator: Engineers select important performance parameters and track them over time, comparing actual, achieved values against expected, or planned, values.

This chart shown is tracking speed. The blue line shows the values the developers planned to achieve over time. At this point, they expected to achieve a speed beyond the threshold; however, the black dots show the actual values achieved so far. The developers have not yet achieved the threshold value for speed, indicating a potential problem area that needs management attention.

[Line graph shrinks and narrator appears] Narrator: Technical performance measures are typically used to monitor the most critical or highest-risk technical requirements. They help reduce risk by identifying potential performance problems earlier during system development so corrective action can be taken.


SELC Technical Reviews

Another tool DHS has put in place to help manage the SE process is a series of technical reviews. This is a diagram of the SELC as it aligns with the Acquisition Life Cycle Framework (ALF). The SELC has nine major activities, and the diamonds along the bottom of the graphic represent the various technical reviews that are held throughout the design and development of the system. Each review compares the system against certain entrance and exit criteria before the system is allowed to move forward from one major activity to the next. This gives program managers and other decision makers periodic insight to the system as it develops to ensure that technical risks are understood and mitigated.

Select each technical review in the diagram below for more information.

D

Click here to view an enlargement.

Properly applied, the SELC should result in systems that meet users' requirements in an efficient, effective, and well-balanced way.


page 26 of 31

Long Description

The ALF consists of four phases: Need, Analyze/Select, Obtain, and Produce/Deploy/Support. Included in the four phases are six acquisition decision events (ADEs), numbered: 0, 1, 2A, 2B, 2C, and 3.

The SELC runs in parallel with the ALF and consists of one recommended, and nine major activities: Needs Analysis (a recommended pre-SELC activity), Solution Engineering, Planning, Requirements Definition, Design, Development, Integration and Test (I&T), Implementation, Operations and Maintenance (O&M), and Disposition. Included are eleven technical reviews: SPR, SER, PPR, SDR, PDR, CDR, IRR, PRR, OTRR, ORR, and PIR.

The SELC Solution Engineering activity aligns with the ALF Analyze/Select phase. The SELC major activities Planning, Requirements Definition, Design, Development, Integration and Test (I&T), and Implementation align with the ALF Obtain phase. SELC major activities are often iterative or concurrent in nature and are not strictly performed in a stepwise or sequential manor, hence the recursive loop shown for Requirements Definition, Design, Development and Integration and Test. SELC major activities Operations and Maintenance and Disposition align with the ALF Produce/Deploy/Support phase.

SPR

At the Study Plan Review (SPR), reviewers assess the adequacy (e.g., sufficient scope, proper methods of analysis) of the Analysis of Alternatives/Alternatives Analysis (AoA/AA) Study Plan.

SER

At the Solution Engineering Review (SER), reviewers analyze the proposed solution for effectiveness, suitability, efficiency, non-duplication, technology, testability, and sustainability.

PPR

At the Project Planning Review (PPR), reviewers evaluate the team\'s planning products and the program\'s readiness to proceed to the Requirements Definition major activity.

SDR

At the Systems Definition Review (SDR), reviewers evaluate the completeness of the system requirements and the program\'s readiness to proceed to the Design major activity.

PDR

At the Preliminary Design Review (PDR), reviewers assess the integrity of the high-level system design and ensure the team is ready to proceed to detailed design.

CDR

At the Critical Design Review (CDR), the program office must demonstrate that its system design is complete and accurate. Reviewers examine the initial product baseline to make their determination.

IRR

At the Integration Readiness Review (IRR), reviewers examine the results of the Development major activity of the SELC, and ensure the system is ready to proceed to Integration & Test.

PRR

At the Production Readiness Review (PRR), reviewers validate that the system, as developed, meets the user\'s requirements, as defined. The PRR supports the Acquisition Decision Event-2C (ADE-2C) decision whether or not to authorize Low Rate Initial Production (LRIP).

OTRR

At the Operational Test Readiness Review (OTRR), reviewers ensure the system is ready to begin Operational Test and Evaluation (OT&E).

ORR

At the Operational Readiness Review (ORR), reviewers examine the results of OT&E to determine whether the system is ready to move into production and (eventually) operation in the field.

PIR

At the Post-Implementation Review (PIR), conducted within six months of initial deployment, reviewers evaluate the program\'s achievement of its baseline goals.

SE

Systems Engineering

SELC

Systems Engineering Life Cycle


Knowledge Check

For each definition below, select the correct technical management process/tool from the drop-down list provided. When you are finished, select Submit.

Assessments conducted throughout the design and development process to gauge progress and readiness to proceedTechnical Reviews

The process systems engineers use to track a system's design evolutionConfiguration Management

Important performance parameters tracked over time to monitor the most critical or highest risk technical requirementsTechnical Performance Measures

Show my answer


page 27 of 31

• Technical Reviews are assessments conducted throughout the design and development process to gauge progress and readiness to proceed.• Configuration Management is the process systems engineers use to track a system's design evolution.• Technical Performance Measures are important performance parameters tracked over time to monitor the most critical or highest risk technical requirements.


End Goal: A Balanced Design

The end goal of SE is to produce the optimum design for a system, one that effectively meets the users' requirements while balancing all of the considerations you see here:

In addition to its performance requirements, the system needs to be safe to operate, affordable, supportable, etc. To accomplish this, the SE process must integrate the competing demands of hardware and software development, testing, production, and support and sustainment, making trade-offs to achieve a balanced design.


page 28 of 31

Safety

Is the system safe for users to operate and maintain?

Affordability

Will the Government get a high return on its investment? Is the system cost-effective to operate and maintain?

Testability

How easy is it to inspect, test, evaluate, and diagnose the system?

Producibility

How easy is the system to fabricate, assemble, inspect, test, and accept?

Interoperability

Does the system work/communicate/exchange data with existing systems?

Disposability

How easy and environmentally safe will it be to dispose of the system at the end of its useful life?

Reliability

How likely is it that the system will complete a mission without breaking down?

Availability

How likely is it that the system will be available and mission ready when needed?

Maintainability

How easy is it to fix the system when it breaks? How quickly can it be repaired?

Human Factors

Have you considered how humans will interact with the system? Was the system designed to reduce operator errors, stress, training requirements, and fatigue? Is it ergonomically and physically suitable for the average operator?

Environmental Impact

How will the system—components, raw materials, chemical consumables, noise and gas emissions, operation, etc.—impact the environment?

SE

Systems Engineering


Knowledge Check

Which of the following best describes the end goal of the systems engineering process?

To produce the optimum system design that meets the user's requirements while balancing considerations such as reliability, availability, affordability, environmental considerations, etc.To ensure that all the user requirements identified during requirements analysis are satisfied by the final system design produced during design synthesis.To ensure that the system as designed meets the user's requirements and is highly supportable and highly producible, regardless of cost.To assemble all the products and processes necessary to produce the components of each item in the optimum design into a product baseline, which should be established by the Critical Design Review (CDR).

Submit


page 29 of 31

The end goal of the systems engineering process is to produce the optimum system design that meets the user's requirements while balancing considerations such as reliability, availability, affordability, environmental considerations, etc.


Knowledge Check

DWhat is the first step of the systems engineering process?

Design Synthesis

Requirements Analysis

Functional Analysis/Allocation

Technical Management Processes/Tools

Submit


page 30 of 31

Long Description

This diagram depicts the three step systems engineering process. In this instance of the diagram, the three steps are not labeled and the first step is highlighted.

Requirements Analysis is the first step of the systems engineering process, followed by Functional Analysis/Allocation, and finally Design Synthesis.


Lesson Summary

Review the key concepts introduced in this lesson.

Systems Engineering (SE) is a systematic approach to designing and developing a solution to meet a requirement. The Government and contractor work together to transform an identified mission need into a fielded system through systems engineering. DHS has established a Systems Engineering Life Cycle (SELC) to guide the technical management of acquisition programs.

The Systems Engineering Process

These three steps of the SE process transform a user’s requirements into a description of the solution:

1. Requirements Analysis (What must the system do, how well, and under what conditions?)

2. Functional Analysis/Allocation (How will the system satisfy the requirements?)

3. Design Synthesis (What components will perform the functions?)

There are three traceability loops between the steps that are vital to the success of the design: the Requirements Loop, the Design Loop, and the Verification Loop. The output of the SE process is a description of a system, which is elaborated to greater levels of detail as the system evolves through development.

Technical Management Processes and Tools

Throughout the process, engineers use a variety of technical management processes and tools to help them make decisions, track their progress, and control the output of the process.

Three examples are:

• Configuration management (CM), the process engineers use to track a system's design evolution andensure the development team is on the same page

• Technical Performance Measures, important performance metrics tracked over time to compare achievedvalues against expected values

• The technical reviews distributed throughout the SELC

You have reached the end of Systems Engineering. To continue, select the next lesson from the Table of Contents.

To print this lesson, select print.


page 31 of 31

Documents

Systems Engineering · PDF file · 2015-12-03meet a requirement. ... Systems Engineering The Government's Responsibilities ... (DT&E) • Government establishes system-level performance