OCR LEVEL 3
CAMBRIDGE TECHNICAL
CERTIFICATE/DIPLOMA IN
IT
SYSTEM DESIGN
R/505/4647
LEVEL 3 UNIT 33
GUIDED LEARNING HOURS: 60
UNIT CREDIT VALUE: 10
TECHNICALS
AIM AND PURPOSE OF THE UNIT
This unit will enable learners to gain an understanding of the processes undertaken in designing an effective business system from understanding the purpose and use of system design tools through to developing a prototype. On completing this unit the learners will be able to use system design tools, design system inputs and outputs and produce a documented prototype.
The Level 3 ‘Systems Analysis’ unit is complementary to this unit and learners may find it helpful to complete both units alongside each other.
System design Level 3 Unit 33
ASSESSMENT AND GRADING CRITERIA
Learning Outcome (LO)
The learner will:
Pass
The assessment criteria are the pass requirements for this unit.
The learner can:
Merit
To achieve a merit the evidence must show that, in addition to the pass criteria, the learner is able to:
Distinction
To achieve a distinction the evidence must show that, in addition to the pass and merit criteria, the learner is able to:
1 Understand how system design tools are used in a business system development.
P1 explain how design tools are used in business system development 2 Be able to use system
design tools in a business system
P2 produce data flow diagrams for a specified business system
M1 develop an entity model with data dictionary for a specified business system D1 design process specifications for primary functions in a specified business system 3 Be able to design system inputs and outputs
P3 produce system input and output designs for a specified purpose
M2 explain the importance of human computer interaction (HCI) considerations when designing system inputs and outputs 4 Be able to produce a
documented prototype for a specified system
P4 create a documented prototype for a specified system
M3 produce user documentation for the prototype for a specified system
D2 evaluate the prototype produced suggesting improvements
relevant examples to their work though these do not need to be the same ones specified in the unit content.
LO1 Understand how system design tools are used in a business system development
• Data flow diagrams (DFD)
- context diagrams, lower levels, data stores, functions, external sources/destinations
• Entity modelling
- entities, relationships, dealing with many to manys
• Process Specifications
- e.g. decision tables structured English, pseudo code, flowcharts etc. • User interface - colour schemes - layout - forms - menus - automation - GUI
LO2 Be able to use system design tools in a business system
• From a requirements specification and notes
- DFDs, entity models,
• Process specifications i.e. a decision table, a flow diagram, pseudo code etc. data dictionary
- tables, field names, types, sizes - data validations
- use of codes to represent data effectively
LO3 Be able to design system inputs and outputs
• Inputs
- forms, screens, direct data entry (bar codes etc.)
• Resources
- use of software applications to generate designs
LO4 Be able to produce a documented prototype for a specified system
• Prototype (database, portal, applications)
- Linked tables, keys (primary, foreign, compound) - Forms and reports, outputs
• Documentation (e.g. structures, relationships, verification options)
• User documentation
- instructions (e.g. paper manual, imbedded guidance etc.)
- training plan for users
• Evaluation
- approaches, changeover (parallel, pilot, phased etc.) - constraints – hardware, software, legacy systems etc. - alternative system solutions
System design Level 3 Unit 33
DELIVERY GUIDANCE
Understand how system design tools are used in a business system development.
Learners should be introduced by the tutor to the classical design tools dealing with data flow, entity relationships and process design with typical exemplars of each. Individuals (or groups) can then use exercises to produce diagrams etc from written descriptions of systems.
Explanations of the tools should include researched exemplars and commentaries on their relevance to system design with any linkages explained.
Learners could be encouraged to research various
approaches to system design and contrast their usage and appropriateness
Be able to use system design tools in a business system
Using the tools covered earlier learners will individually develop system designs for a specific system – requirements for a specific system to be provided by the tutor. From this case study (could include answers to questions) learners can interactively devise DFDs and associated diagrams.
Be able to design system inputs and outputs
The tutor should introduce learners to the ideas of what makes an effective I/O interface for users. Examples and research (using the internet if necessary) could be used to locate and examine good and bad interfaces.
Discussion could be used to draw out factors that make good interfaces particularly when collecting information (inputs) as well as displaying it (outputs). Paper input and output options should be considered with learners examining and evaluating live documents such as college enrolment forms or order forms.
In teams, learners could research HCI to enable them to track the developing area of HCI factors, particularly as it is affected by disability legislation, reporting back their findings with examples.
Be able to produce a documented prototype for a specified system
The system designed in Learning Outcome 2 could be converted to a simple prototype using (typically) a database package to produce a set of linked tables with associated keys, screens and report designs.
The tutor should ensure that the learners are fully appreciative of the need to document structural detail for the prototype to support future revisions, developments etc. This may be annotations added to a specification provided or additions to an outline specification they have prepared themselves or in team work.
The tutor will outline what is included in typical user
documentation and learners can choose to document systems manually or as part of the prototype. Learners could research alternative implementation strategies and present findings and strengths and weaknesses of each.
The tutor will outline the use of success criteria and learners evaluations will include judging how near the prototype is to being a successful solution and what alternatives could be considered (e.g. full or partial solutions). Learners could share this information with the wider group.
sign tools used in a business system development and explain how they are used by a system designer. One clear example of each tool (DFD, entity model and process specification) will be required.
Assessment Criteria P2, M1, D1
For P2 learners should be given a simple business system specification for a user requirement (e.g. a stock control system, a web based ordering system or a CRM system etc). The learners must produce DFDs for a specified business system (at least 2 levels and with 4 functions, including at least one data store).
For merit assessment criterion M1 learners must develop an Entity model and data dictionary from the specification. Sample documents should be accurate and keys for all entities should be identified.
For distinction criterion D1 Learners must design 3 different process specifications for primary functions in a specified business system.
Assessment Criteria P3, M2
For P3 learners must produce suitable system input and output designs using the system specification provided (or another if appropriate). . Three different forms and three varied reports should be produced. It is acceptable to use software to design the products (e.g. that found in database design packages).
For merit assessment criterion M2 learners must explain the importance of HCI considerations when designing systems inputs and outputs this could relate to the designs produced for P3. This could be in the form of a presentation or report and should include a range of consid-erations as listed in the teaching content.
Assessment Criteria P4, M3, D2
For P4 the learner must create a prototype for the specified system with supporting documentation of the structure. The prototype should include items listed in the teaching content.
For merit assessment criterion M3 learners must produce user documentation for a prototype for a specified system; this could be for the prototype designed in P3.
For distinction criterion D2 learners must evaluate the prototype produced in P4 suggesting improvements. The evaluation should consider the areas outlined in the teaching content and more than one alternative approach should be suggested.
System design Level 3 Unit 33
RESOURCES
Evidence could be generated manually or by using specialist software depending on centre resources and learner preferences.
MAPPING WITHIN THE QUALIFICATION TO THE OTHER UNITS
Unit 20 Impact of the use of IT on business systems
Unit 25 Data analysis and design
Unit 34 Systems analysis
LINKS TO NOS
4.1 System Architecture
4.2 Data Analysis
4.3 Human Needs Analysis
4.4 System Analysis
4.6 Human Computer Interaction Interface (HCI) Design
