Ondřej Přibyl L3: System Development Life Cycle page 1 Lecture 3: System Development Life Cycle Doc.Ing. Ondřej Přibyl, Ph.D. Department of applied mathematics Faculty of Transportation sciences, CTU Telematics systems and their design

Ondřej Přibyl L3: System Development Life Cycle page 2 Faculty of Transportation Sciences, CTU Telematics systems and their design Quick review from Lecture 2 1.What does it actually mean „ System analysis and design “ ? 2.What is a difference between Analysis and Design? 3.Major system development life stages 4.Who is System analyst? How a job description for a system analyst looks like? 5.What are the reason for IT(S) project failures? 6.What does it mean Cost of change? 7.What is a Capability Maturity Model? 8.Who is a stakeholder?

Ondřej Přibyl L3: System Development Life Cycle page 3 Faculty of Transportation Sciences, CTU Telematics systems and their design Lecture 2 – Overview Topics from Lecture 1 will be discussed in more details Part I: Introduction Part II: System Development Life Cycle (SDLC) and its phases

Ondřej Přibyl L3: System Development Life Cycle page 4 Part I: Introduction

Ondřej Přibyl L3: System Development Life Cycle page 5 Faculty of Transportation Sciences, CTU Telematics systems and their design Process of System Development System development process – a set of activities, methods, best practices, deliverables, and automated tools that stakeholders use to develop and continuously improve information systems and software –Many variations –Using a consistent process for system development: Create efficiencies that allow management to shift resources between projects Produces consistent documentation that reduces lifetime costs to maintain the systems Promotes quality

Ondřej Přibyl L3: System Development Life Cycle page 6 Faculty of Transportation Sciences, CTU Telematics systems and their design Principles of System Development Get the system users involved. Use a problem-solving approach. Establish phases, activities and deliverables. Document through development. Manage the process and projects. Justify systems as capital investments. Don’t be afraid to cancel or revise scope. Divide and conquer. Design systems for growth and change.

Ondřej Přibyl L3: System Development Life Cycle page 7 Faculty of Transportation Sciences, CTU Telematics systems and their design Use a Problem-Solving Approach Classical Problem-solving approach –Study and understand the problem, its context, and its impact. –Define the requirements that must be meet by any solution. –Identify candidate solutions that fulfill the requirements, and select the “best” solution. –Design and/or implement the chosen solution. –Observe and evaluate the solution’s impact, and refine the solution accordingly. Case study: Your car stopped and is not starting any more. Diagnose its problem using a problem solving approach

Ondřej Přibyl L3: System Development Life Cycle page 8 Faculty of Transportation Sciences, CTU Telematics systems and their design Major steps in system development life cycle System Analysis System Design Request for a new system System Implementation System Maintenance Feasible solutions and system requirements Design specificationPrototype / Working version Post implementation review Request for modification Project Planning

Ondřej Přibyl L3: System Development Life Cycle page 9 Faculty of Transportation Sciences, CTU Telematics systems and their design The Classic Project Phases

Ondřej Přibyl L3: System Development Life Cycle page 10 Faculty of Transportation Sciences, CTU Telematics systems and their design Establish Phases and Activities

Ondřej Přibyl L3: System Development Life Cycle page 11 Part II: The Systems Development Life Cycle (SDLC)

Ondřej Přibyl L3: System Development Life Cycle page 12 Phase I: Planning

Ondřej Přibyl L3: System Development Life Cycle page 13 Faculty of Transportation Sciences, CTU Telematics systems and their design Project planning This phase is the fundamental process of understanding why an information system should be built. The Planning phase will also determine how the project team will go about building the information system. This phase provides decision support materials

Ondřej Přibyl L3: System Development Life Cycle page 14 Faculty of Transportation Sciences, CTU Telematics systems and their design Two Planning Steps During project initiation, the system’s business value to the organization is identified –How will it lower costs or increase revenues? –Is it really cost effective? During project management, the project manager –creates a work plan, –staffs the project, and –puts techniques in place to help the project team control and direct the project through the entire SDLC.

Ondřej Přibyl L3: System Development Life Cycle page 15 Faculty of Transportation Sciences, CTU Telematics systems and their design Scope Definition Problem statement – a statement and categorization of problems, opportunities, and directives; may also include constraints and an initial vision for the solution. Synonyms include preliminary study and feasibility assessment. Constraint – any factor, limitation, or restraint that may limit a solution or the problem-solving process. Scope creep – a common phenomenon wherein the requirements and expectations of a project increase, often without regard to the impact on budget and schedule. Statement of work – a contract with management and the user community to develop or enhance an information system; defines vision, scope, constraints, high-level user requirements, schedule, and budget. Synonyms include project charter, project plan, and service-level agreement (SLA).

Ondřej Přibyl L3: System Development Life Cycle page 16 Faculty of Transportation Sciences, CTU Telematics systems and their design Decision Analysis Candidate solutions evaluated in terms of: –Technical feasibility – Is the solution technically practical? Does our staff have the technical expertise to design and build this solution? –Operational feasibility – Will the solution fulfill the users’ requirements? To what degree? How will the solution change the users’ work environment? How do users feel about such a solution? –Economic feasibility – Is the solution cost-effective? –Schedule feasibility – Can the solution be designed and implemented within an acceptable time? –Risk feasibility – What is the probability of a successful implementation using the technology and approach?

Ondřej Přibyl L3: System Development Life Cycle page 17 Phase II: Analysis

Ondřej Přibyl L3: System Development Life Cycle page 18 Faculty of Transportation Sciences, CTU Telematics systems and their design System analysis Analysis specifies what the system should do The analysis phase answers the questions of –who will use the system, –what the system will do, and –where and when it will be used. During this phase the project team investigates any current system(s), identifies improvement opportunities, and develops a concept for the new system.

Ondřej Přibyl L3: System Development Life Cycle page 19 Faculty of Transportation Sciences, CTU Telematics systems and their design Three Analysis Steps 1.Analysis strategy: This is developed to guide the projects team ’ s efforts. This includes an analysis of the current system. 2.Requirements gathering: The analysis of this information leads to the development of a concept for a new system. This concept is used to build a set of analysis models. 3.System proposal: The proposal is presented to the project sponsor and other key individuals who decide whether the project should continue to move forward. –The system proposal is the initial deliverable that describes what business requirements the new system should meet.

Ondřej Přibyl L3: System Development Life Cycle page 20 Phase III: Design

Ondřej Přibyl L3: System Development Life Cycle page 21 Faculty of Transportation Sciences, CTU Telematics systems and their design Design states how to accomplish the objective In this phases it is decided –how the system will operate, in terms of the hardware, software, and network infrastructure; –the user interface, forms, and reports that will be used; and –specific programs, databases, and files that will be needed.

Ondřej Přibyl L3: System Development Life Cycle page 22 Faculty of Transportation Sciences, CTU Telematics systems and their design Four Design Steps 1.Design Strategy: This clarifies whether the system will be developed by the company or outside the company (outsourcing strategy) Discussion: Advantages and disadvantages of outsourcing? 2.Architecture Design: This describes the hardware, software, and network infrastructure that will be used. 3.Database and File Specifications: These documents define what and where the data will be stored. 4.Program Design: Defines what programs need to be written and what they will do (use cases, functions, modules)

Ondřej Přibyl L3: System Development Life Cycle page 23 Phase IV: Implementation

Ondřej Přibyl L3: System Development Life Cycle page 24 Faculty of Transportation Sciences, CTU Telematics systems and their design System Implementation During this phase, the system is either developed or purchased (in the case of packaged software). This phase is usually the longest and most expensive part of the process.

Ondřej Přibyl L3: System Development Life Cycle page 25 Faculty of Transportation Sciences, CTU Telematics systems and their design Three Implementation Steps System development/construction: The system is built and tested to make sure it performs as designed. Discussion: How much testing would you expect for a one month of SW development? Installation: Prepare to support the installed system. Support Plan: Includes a post-implementation review. Are there different tests done? Unit tests Software factory test (SFAT) System integration tests (SIT) Proof of Performance (POP) Stress test, load test, … User Acceptance Test (UAT) …

Ondřej Přibyl L3: System Development Life Cycle page 26 Phase V: Maintenance and operation

Ondřej Přibyl L3: System Development Life Cycle page 27 Faculty of Transportation Sciences, CTU Telematics systems and their design System Operation & Maintenance System support – the ongoing technical support for users of a system, as well as the maintenance required to deal with any errors, omissions, or new requirements that may arise.

Ondřej Přibyl L3: System Development Life Cycle page 28 Cross Life-Cycle Activities

Ondřej Přibyl L3: System Development Life Cycle page 29 Faculty of Transportation Sciences, CTU Telematics systems and their design Cross Life-Cycle Activities Cross life-cycle activity – any activity that overlaps many or all phases of the systems development process. –Fact-finding Fact-finding - the formal process of using research, interviews, meetings, questionnaires, sampling, and other techniques to collect information about system problems, requirements,and preferences. –Documentation and presentation Documentation – the ongoing activity of recording facts and specifications for a systems for current and future reference. Presentation – the ongoing activity of communicating findings, recommendations, and documentation for review by interested users and mangers. Repository – a database and/or file directory where system developers store all documentation, knowledge, and artifacts for one or more information systems or projects. –Feasibility analysis –Process and project management

Ondřej Přibyl L3: System Development Life Cycle page 30 Faculty of Transportation Sciences, CTU Telematics systems and their design System Development Documentation, Repository, and Presentations

Ondřej Přibyl L3: System Development Life Cycle page 31 End of Lecture 3