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Design and Development of Information Systems (Part 1)

Design and Development of Information Systems (Part 1)

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Design and Development of Information Systems (Part 1)

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  1. Design and Development of Information Systems(Part 1) Yung-Fu Chen, Ph.D. Department of Health Services Management, China Medical University

  2. Discuss the stages Evaluate the strengths and Describe methodologies that State the purpose of data modeling Discuss the benefits of using Define the customary steps Describe the differences between Differentiate List and describe Describe he purpose Distinguish the various Describe two techniques for process modeling Identify the differences between Discuss the concept and benefits of object-oriented modeling Learning Objectives

  3. Outline • Design and Development of Information Systems • Systems Development Life Cycle • New Approaches and New Tools • Use of New Approaches for Analysis and Design • Developing Data Model Diagrams

  4. Systems Development Life Cycle • Four stages for traditional SDLC • System planning • System development • System implementation • System operation Table 5-1. SDLC

  5. Systems Development Life Cycle • System analysis and design methodologies • Model-driven approach • Structure analysis • Waterfall methodology • Information engineering • Object-oriented analysis • Accelerated analysis technique • Prototyping to identify user information and system needs

  6. Waterfall methodology One of the first approaches for information systems analysis and design Follows the SDLC in sequence, like water cascading over a waterfall A structured, model-driven, and process-oriented approach Documented by models such as data flow diagram (DFD) describing the system processes and their associated inputs, outputs, and storage needs Drawbacks Not including the development of IS based on an enterprise information model Extremely time-consuming. Using prototyping and RAD tools to help reduce the drawback Not sufficient emphasis on end-user input in the development process. Use of rapid prototyping, scenario-based development and JAD to help minimize this drawback Application development is performed with little or no consideration of the overlap between other existing applications and current projects Systems Development Life Cycle

  7. New Approaches and New Tools • Information engineering • Based on a holistic view of an enterprise’s information requirements, hence it is flexible and able to accommodate changes in organizational structure and/or changes in emphasis of the external environment. • The modeling process considers the goals of the enterprise, identifies data requirements, identifies processes to be supported, and sets priorities for implementation • Information models are represented in entity relationship diagram (ERD)

  8. An outpatient clinic treats several patients per day. Each patient is seen by a primary-care provider. Each patient may also have ancillary services performed including laboratory, radiology, or other types of test Identify the various processes and groups of data required to support each process Processes include patient registration, patient examination, performance of diagnostic tests Various groups of data about the patient to support the registration, examination, and diagnostic processes, such as patient’s name, birthday, medical record number, and sex the visit, such as date of visit, time of the visit, chief complaint, final diagnosis, and disposition of the patient The primary-care provider who saw the patients, such as clinician name and clinician ID number The tests that the patient received, such as name of the tests, ID number of the test New Approaches and New Tools • Represent information model in entity relationship diagram (ERD) • An entity in defined as a person, place, thing, or concept about which data are gathered, such as patient, patient visit, primary-care provider, and tests • Each ERD shows relationships between entities. For example, patient is related to patient visit (Figure 5-1) • Data independent • Data do not dependent on a specific application that all the data can be used by all applications

  9. MedRecNo LName FName MInitial BDate Sex EncounterNo EncounterDate ChiefComplaint AttendingMD Final Diagnosis Patient Patient Visit Figure 5-1 Simple Entity Relationship Diagram The entity Patient is related to the entity Patient Visit because every patient coming to the clinic, hospital, or physician’s office has a patient visit.

  10. New Approaches and New Tools • Computer-aided software engineering tools • Development of IS relies heavily on charts and graphics, such as DFD, ERD, data dictionaries, and other types of tables and schematics • CASE tools are used to help with system analysis and design and the creation of such diagrams and models

  11. New Approaches and New Tools • Object-oriented (O-O) analysis • The waterfall method is a structured method focusing on modeling and organization’s processes • IE modeling focuses on modeling the organization’s data • O-O analysis integrates modeling the organization’s processes and data into objects that each integrates individual processes and data

  12. Object-oriented (O-O) analysis An object include the operations or processes to perform on the data (properties), which an entity contains only data All objects are assigned to a class with the benefit that the subclass of objects inherits the properties of the high class Object models use the unified model language (UML) to provide standardized diagram techniques, syntax, and notation to make it easy to document system development Rational Rose (Rational Software) Visible Analyst (Visible System) Visual Studio (Microsoft) New Approaches and New Tools

  13. Person Last Name First Name Middle Name DOB Insert Last Name Insert First Name Insert Middle Name Insert DOB Figure 5-2. Object-Orient Model • The objects Patient and Physician are assigned to the class Person. • One benefit of O-O analysis is that attributes and methods are not repeated separately for each object in a class. This makes updating or changing attribute and methods for a particular class or subclass much easier and ensures better consistency of data. Object Class Attributes Methods/Behaviors Physician Patient Provider # Credentials Insert Provider # Insert Credentials Delete Provider # Delete Credentials Medical Record # Insurance Co. Insert Medical Record # Insert Insurance Co. Delete Insurance Co.

  14. Rapid application development Attempt to address the weaknesses of the traditional structured waterfall approach by using an interactive prototype approach to development and engaging end user in all parts of the process By using the following techniques, RAD can develop IS quickly JAD and other CASE tools and 4G visual language Getting the critical essentials of a project developed within a limited time period Adjusting the SDLC phases, RAD methodology Joint application development Provide an opportunity for substantial end-user input and speeds the development process Team consists of a group of end-users, analysts, and technique development professionals A trained facilitator develops the agenda (Table 5-2) for the session and guides the discussion A report is presented by including all of the findings the as-is system, conformation of the to-be system goals and objectives, identification of new system functions, and determination of development phases and the timeline New Approaches and New Tools

  15. Table 5-2. JAD Agenda Joint Application Design Session Nov. 8, 9_ _ Clinical Registration and Application Scheduling System Facilitator: Y. F. Chen Scribes: A. M. Williams J. M. Ludwig R. J. Johns

  16. New Approaches and New Tools • Phased approach • A primary element is determining the phase of system development and priority • Break the whole system into a series of smaller versions • 1st version: the most critical and fundamental requirements such as the admission-registration-transfer (ADT) system • 2nd version: an order entry system • 3rd version: a results reporting system • A strict time frame is placed on each phase

  17. Prototyping allows for maximal user input and helps to speed up development process is an interactive process to develop the external features, such as design of screen, interaction between screens, and reports, of a system does not usually include a working database or actual program code, but only provides the “touch and feel” of the system to be designed needs CASE tools, such as 4GL, screen generators, code generators, and program templates, to speed up the development process has several benefits It increases end user involvement in the analysis and development process It can be developed quickly It provides the look and feel of the real system to be designed New Approaches and New Tools

  18. Administrator Practitioner Patient Client Policymaker Physician Health Information Manager (Information Broker) Chapter 4 Information Services • Information Engineering • Strategic Planning • Data Modeling • Process Modeling • Data Administration • Interface Design • Screen • Reports • Information Retrieval • Search Strategies • Database Languages • DSS Development • DSS Use • Information Analysis • DSS Use • Statistical Analysis • Data Presentation • Policy Development • Security • Information Engineering • Information Retrieval • Information Use Chapter 5 Figure 4-1. Information Engineering Function

  19. Use of New Approaches for Analysis and Design • Data modeling • Once the strategic planning efforts are completed, the process of data modeling will follow • An example which describes the outcomes of the strategic planning for 350-bed acute-care hospital • CSFs • Provide quality care • Have efficient operations • Develop good physician relations • Obtain optimal reimbursement and care mix • Have a high perception of efficiency and service by various constituents • Following the strategic planning process, the hospital’s IS committee started to integrate the long-range IS plan with the business plan by developing IS that supported the monitoring and achievement of the CSFs • Table 5-3 show a sample of IS matrix for the quality-of-care CSFs

  20. Table 5-3. Quality-of-Care CSF and IS Matrix

  21. A definition of data modeling A model is defined as a small copy or imitation of an existing object Data model is used as the plan for building complex organization database. The models should describe how data flow, the requirements and usage of the data, and the attributes of the data Data modeling is the first essential step in ensuring successful database and application development Figure 5-3 represents data requirements of an emergency department encounter Categories of data models Conceptual data model (schema) defines the database requirements of the enterprise in a single database description is used as the basis for development of external and internal models External (logical) data model is the view of the data by a specific group of users or a processing application, such as admitting personnel, nursing service, HIM department, human resources, and central supply (Figure 5-4) Internal (physical) data model depicts how the data are physically represented in the database whose development concerns with data structures, file organizations, and mechanisms and techniques to most efficiently store data and make use of the DS Use of New Approaches for Analysis and Design

  22. Person Payer ID Patient MR NO LName FName Gender DOB Street Address Apartment City State Insurance No ZIP Figure 5-3. Conceptual Data Model of Emergency Department Project: Emergency Room Encounter. Model: ER_PROJECT Author: John Version: 1 02/28/-- Conceptual Data Model Professional Staff Employed ID Encounter Encounter NO TimeArrival DateArrival ArrivalMode ChiefComplaint Disposition DateDisposition TimeDisposition DischDX Test-Treatment Accession NO Test ID DTime Order DTime Collect DTime Complete Physician DrNumber

  23. Figure 5-4. Relationship Between Conceptual and External Views

  24. Use of New Approaches for Analysis and Design • Content of a conceptual or business data model • A business data model usually contains the following elements • Diagram provides a picture of the data needs of the enterprise • Glossary defines every name that is documented on the data diagram (Figure 5-5) • Narratives help explain what the diagram and glossary mean, which are useful adjuncts to communicate to both users and developers what the data model diagram is trying to convey • Access pattern is important for the physical database developer to know what data are accessed, how often these data are accessed, and in what order they are accessed

  25. Figure 5-5Glossary Description

  26. Data modeling methods and styles Popular data modeling methods (Figure 5-6) Chen entity relationship (ER) Information engineering (IE) Nijssen’s information analysis methodology (NIAM) Regardless of methodology, there are several common concepts shared All information is based on entities and relationships among them Additionally, an attribute is a fact or piece of information describing an entity The data model diagram names each entity, defines each entity by its attributes, and show relationships among various entities (Fig. 5-7) Use of New Approaches for Analysis and Design

  27. has M 1 Patient Encounter Patient Encounter Patient Encounter Figure 5-6Comparison of Conceptual Data Model Notations CHEN-ER Diagram Information Engineering Diagram Bubble Diagram

  28. MEDRECNO LNAME FNAME MINITIAL GENDER BIRTHDATE Patient Figure 5-7Relationship Between Patient and Emergency Encounter Entity ENCOUNTER NO ENCOUNTER DATE CHIEF COMPLAINT ATTENDING MD NO Emergency Department Encounter Relationship Attribute

  29. Use of New Approaches for Analysis and Design • Steps in the data modeling process • Formation of the data modeling/planning team • Determination of the planning tools that will be used • Studying user requirements and defining these through the use of data modeling diagrams • Development of the database design

  30. Formation of the data modeling/planning team The team will be composed of user representatives, IS analysts, and database specialists Must have support of top management Must have a clear understanding about the purpose, expected outcomes, and benefits of the projects 2. Determination of the planning tools that will be used CASE software helps create and compile various types of analysis tools, such as data flow diagrams (DFDs, see Fig. 5-8), data dictionaries (DDs), entity relationship diagrams (ERDs), and other charts, tables, and schematics CASE provides an convenient and effective mechanism to update data model diagrams, charts, and tables CASE imposes standardization CASE allows for automatic consistency checks Use of New Approaches for Analysis and Design Steps in the data modeling process

  31. Figure 5-8Sample Data Flow Diagram RegisterPatient Transformation orOperation Patient External entity Registration Data RegisterPatient Data flow Admit Data RegisterPatient RegisterPatient Order Sheet History and Physical Progress Notes Test Results Patient File Database

  32. 3. Defining user requirements Identify the scope of the project Collect data about the user requirements Adjuncts and aids in identifying user requirements Document data flows, data relationships, uses, and requirements 4. Development of the database design See the following Section and the following Chapter Use of New Approaches for Analysis and Design Steps in the data modeling process

  33. Part 2Developing Data Model Diagrams

  34. Developing Data Model Diagrams • As mentioned in the previous section, Chen-ER, NIAM, and IE methods are popular methods for development of data model diagrams • In this section IE method developed by James Martin is used to illustrate how a data model diagram may be developed because of its popularity, ease of use, and concept of top-down development

  35. Martin IE style Stage of the Martin IE method IE concepts and methods of notation Identifying primary entities Identifying relationships among entities Determining primary and alternate identifiers Determining non-key attributes Validating the model through normalization Determining alternate business rules Integrating the model with existing models Analysis for stability and growth A sample data modeling diagram project Translation of the conceptual data model to a physical data model Process modeling techniques Data flow diagrams Data flow diagram hierarchy Use cases Object-oriented modeling O-O modeling concepts Unified modeling language Benefits of O-O modeling Developing Data Model DiagramsOutline

  36. Stages of the Martin IE method 1. Information strategy planning Concerns how IS can support the strategic goals and how IT can be used to improve competitive position Technological opportunities are identified to support CSFs ISP includes the basic functions of the enterprise and produces an overview ERD of the enterprise, its departments, and its functions 2. Business area analysis CSFs determine (1) which business areas should be the top priorities for analysis; (2) what are the processes and data necessary to make these unit operate optimally; and (3) how do the work processes and data interrelate 3. System design stage Decomposition diagrams, DFDs, data structure diagrams, as well as screen and report layout are used at this stage 4. Construction of the system Use of code generator to generate computer code Supervision and control of transforming logical and physical design specifications to implementation of the physical system design Tasks include (1) developing an implementation schedule, monitoring and controlling implementation, creating programs and data structures, and developing user and program documentation Martin IE style

  37. Martin IE style IE concepts and methods of notation • There are several mechanical steps in the development of a data model. Each should be done in sequence to help in developing a robust model • Identifying primary entities • Identifying relationships among entities • Determining primary and alternate identifiers • Determining all non-key attributes • Validating the model through normalization • Determining attribute business rules • Integrating the model with existing models • Analyzing the model for stability and growth

  38. ID Number Name Sex Birthdate Address Patient Martin IE style IE concepts and methods of notation • Identifying primary entities • To develop a data model, entities must be identified, their attributes must be defined, and relationships between entities must be described • An entity is anything about which data can be stored, which is usually a noun (Figure 5-9) Figure 5-9. Entity Representation

  39. Martin IE style IE concepts and methods of notation • Identifying relationships among entities • Relationships are usually verbs • Many different types of relations among data • One-to-one (Fig. 5-10) • One-to-many (Fig. 5-11) • Many-to-many (Fig. 5-12) • One-many-none (Fig. 5-13) • One and only one (Fig. 5-14) Figure 5-10. One-to-One Relationship ID Number Name Sex Birthdate Address Bed Number Patient Bed

  40. Figure 5-12. Many-to-Many Relationship Figure 5-11. One-to-Many Relationship ID Number Name Sex Birthdate Address Order ID Date Time Patient Order ID Number Name Sex Birthdate Address Order ID Date Time Patient Order

  41. Figure 5-14. One and Only One Relationship Figure 5-13. One-Many-None Relationship ID Number Name Sex Birthdate Address Test ID Test Name Patient Test ID Number Name Sex Birthdate Address Clinic ID Clinic Name Patient Clinic

  42. Determining primary and alternate identifiers Primary key: An attribute (or a set of attributes) that uniquely identify a particular occurrence of an entity (i.e. Medical Record # in Table 5-4) Secondary key Attributes chosen as alternatives for identifying specific instances of an entity (i.e. LNAME+BDATE+SEX) Determining non-key attributes After primary and secondary attributes are identified, non-key attributes are identified Non-key attributes are descriptions that are associated with the entity Example: STREET, ADDRESS, etc. Martin IE style IE concepts and methods of notation

  43. Table 5-4. Example of Entity Patient Primary key Primary key Non-key attributes

  44. Validating the model through normalization Normalization refers to how data items are grouped together Examining groups of data to determine structural redundancies or inconsistencies due to wrong assignments (i.e. associate “lab test #” to “patient” rather than “lab test” Determining attribute business rules Business rules govern the integrity of an entity and determine certain properties or values that an attribute may have. For example, data type, length, format, uniqueness of value, allowable values, and default values Also refer to triggering operations which are rules that determine the correctness or incorrectness of data values Martin IE style IE concepts and methods of notation

  45. Integrating the model with existing models In practice, data models for different functions are developed in parallel or sequentially, hence inconsistencies and overlaps will occur during consolidation Consolidation of data model consists of comparing mappings and definitions of the models and the business conceptual schema Analysis for stability and growth Future significant changes should be incorporated into the data model so that it will need to be changed frequently and thus remain stable while still allowing for growth Martin IE style IE concepts and methods of notation

  46. Mt. Pleasant Hospital has completed its strategic planning process and has identified five CSFs Provide quality care Have efficient operations Develop good physician relations Obtain optimal reimbursement and care mix Have a high perception of efficiency and service The Emergency Department was identified as a priority area because it was associated with all five CSFs There was room for improvement in the QOC provided in the ED The operations of ED were less than efficiency Attending physicians has complained on numerous occasions about ED inefficiencies Data for patient bill generation were not satisfactory Patient satisfaction surveys has indicated that patients who used the ED were less than favorable about wait times A sample data modeling diagram project

  47. A sample data modeling diagram project • Steps in evaluating the ED • To form a team of users, analysts, and database specialists to identify data flow in the department and result in the DFD appears in Figure 5-15 • To collect some demographic information about the patient care and flow in the ED • To design the IS needed for ED support by reviewing the enterprise data model diagram, as shown in Figure 5-16 • The shaded part in Figure 5-17 shows the entities of interest for developing the ED IS • Figure 5-18 provides a schematic of the principal entities, their relationships, and attributes that represent the ED functions

  48. Figure 5-15 Data Flow of ED Process Patients arrive either by walk-in or some other ways (helicopter, ambulance, etc.) 1.0, 2.0, 3.0, 4.0, 5.0 indicates five department entities represented with Level 0 DFD

  49. Figure 5-16 Enterprise Data Model: ED Conceptual Schema ED is an entity with a one-to-one relationship with Mt. Pleasant hospital Other entities related to the ED

  50. Figure 5-17 Patient Encounter Relationships The shaded parts show the entities of interest for developing the ED IS