SD 2.3: Investigation of Feasibility



		SD 2.3: Investigation of Feasibility

SD2.3 - Realisierbarkeit untersuchen

Contents
Product Flow
Handling
Roles
Methods

Tools Requirements
External Norms
Pre-Tailoring forms

Contents		Product Flow Handling Roles Methods		Tools Requirements External Norms Pre-Tailoring forms

Product Flow

From		Product		to		Methods	Tool Req.	Ext. Norms
Activity	State	Chapter	Title	Activity	State	Methods	Tool Req.	Ext. Norms
External	-	All	Product Information	-	-			/ISO IEC 12207/ Devlp. Proc.: Sys. Arch. Design
PM5	accepted	Existing	Cost/Benefit Analysis	-	-
SD1	accepted	Existing	User Requirements	-	-
SD2.1	being proc.	Existing	System Architecture	-	-
-	-	3.2	System Architecture. Feasibility Studies	SD2.1 PM5	being proc.	BA SIMU	SSD18 SSD19

+ "Chapter" are extra columns from the original printed version of GD 250

* Investigating the Use of Off-the-Shelf Products

It is the primary task of the feasibility study to evaluate the availability of suitable off-the-shelf products under the aspect of a preferred use of off-the-shelf-product. To do so the market is investigated with regard to the suitability of off-the-shelf products, based on the User Requirements. The aim is to identify products that might cover parts of the System. The adequacy of effort spent on the market analysis must be justified with regard to its economic aspects. The results of the market analysis have to be used as a basis for the definition of the System Architecture.

* Definition of Evaluation Criteria

Evaluation criteria for the solution proposals must be defined as the basis for the feasibility study. The criteria must be prioritized and weighted. The criteria must consider aspects like interface complexity, usability of off-the-shelf products, adequacy of technical concepts and of development standards.

* Evaluation of Feasibility

The solution proposals of the technical System Architecture have to be investigated to ascertain if they meet the user-level requirements (fields); after that they must be evaluated on the basis of the defined criteria.

The technical design decisions have to be checked and analyzed to establish critical (sub-) products to be realized. Requirements for personnel, training, organization, logistics, infrastructure, and environmental protection must be taken into consideration.

The effects of the possible solutions on the user organization have to be evaluated on the basis of the Cost/Benefit Analysis. This mainly refers to the practical realization and profitability (available or planned posts, availability of suitable personnel resources, personnel development concepts, agreement between solution proposals and personnel legislation/wage agreements, etc.).

* Realization of Special Considerations about the IT Security

When investigating feasibility, the following has to be observed with regard to IT security:

The selection of IT and non-IT measures, the technical feasibility, the profitability and the toleration of the residual risk have to be checked.

It has to be checked if the IT security-relevant portion possibly can be separated from the non-IT security-relevant portion is possible.
When designing the System it has to be checked if the IT Security Portion can be sufficiently separated. The size of the entire IT security portion (IT security-specific and IT security-relevant functions) which is the object of the evaluation must be as small as possible, particularly if a high E-level is desired.

In case the control of the information flow is an IT security objective, it must be checked if it is possible in the structuring of the System to disentangle adequately the System Architecture elements which later, during operation, run with different classifications (different security levels), or, if based on strong dependences among individual elements, covert channels are already preprogrammed.

---------- The following part is an extension of the original printed version of GD 250 -----------

Roles

Role	Participation
Project Leader	cooperating
System Analyst	cooperating
System Designer	responsible
IT Representative	cooperating
IT Security Representative	cooperating

Methods

Product Methods Allocation Use
Chapter 3.2
System Architecture.
Feasibility Studies BA - Benefit Analysis ⁽¹⁾ Generate
SIMU - Simulation Models ⁽²⁾ Generate

Product	Methods Allocation	Use
Chapter 3.2 System Architecture. Feasibility Studies	BA - Benefit Analysis ⁽¹⁾	Generate
SIMU - Simulation Models ⁽²⁾	Generate

Notes:

(1) Method BA is to be applied if
- a complex decision has to be made and if
- that decision is not based on external factors (i.e. factors beyond the evaluation criteria)

(2) Method SIMU is to be applied if reliability requirements are high nd the use conditions are so complex that static investigations with regard to feasibility and resource requirements are not sufficient.

Tools Requirements

Product	Functional Tools Requirements
Chapter 3.2 System Architecture. Feasibility Studies	SSD18 - Estimating Performances SSD19 - Simulating Timing Behavior

External Norms

Norm	Process	Chapter	Obs.
/ISO IEC 12207/	Development Process	System Architectural Design	(s. Part 3 - ISO 3.2.1)

Pre-Tailoring forms

Pre-tailoring Forms	SD Products																		Implementing Conditions
Pre-tailoring Forms
Small Administrative IT Projects
Medium Administrative IT Projects
Large Administrative IT Projects
Small/Medium Technical-Scientific IT Projects
Large Technical-Scientific IT Projects
Selection, Procurement and Adjustment of Off-the-Shelf Products